Remember that high-tech collar worn by Astro, the talking dog on the Jetsons? Now we know what it was — a GPS from Garmin for tracking him down when he got lost in space. And now you can get one too, especially useful if you have a dog like my ol’ Lab Mocha, who delighted in disappearing in the tall grass to track down a squirrel, coyote, or foxglove (a sure sign of summer).

The Garmin Astro system includes a handheld GPS device and the DC-30 collar, which has a GPS transmitter and is weighted in such a way that the antenna always points skyward. To use it, you haul the two pieces outside, turn on the handheld and transmitter, and wait for satellite signals. Then you attach the collar to your dog and turn him or her loose.

Every few seconds, your pup’s position is transmitted to your handheld, and you can see his or her current position on the map page of your handheld. A Dog Tracker page provides current status: whether the pooch is running, sitting, on point, or bounding around the base of a tree.

If you have multiple dogs, you can track them all on a single device — up to 10 at a time — at a distance of up to seven miles away (depending on what the terrain is).

Rat Raway, Reorge!

Garmin’s known for its global positioning system devices, so it makes sense that the company would include a GPS in its heart rate monitors.

The Forerunner 405 fits in this category. Priced around $350, the Forerunner is loaded with training features for the serious athlete. Regarding basics, it’ll monitor your time, distance, pace, calories and heart rate. Each session (or run or walk or swim) is stored in memory for later review. You can also download that data wirelessly to your computer when it’s in range and turned on, to maintain a workout log.

The silver bezel around the face of the monitor is actually a touchscreen. You use that bezel to make a selection, toggle menu options and change pages. To switch modes, you keep your finger on one of four labeled areas. You put two fingers on the bezel to turn on a backlight. Once you have the display in front of you that you want to maintain, the device allows you to lock it in by pressing enter and quit at the same time.

Because the monitor includes a GPS, you’ll have to wait a few minutes for the GPS satellite signals to be acquired. (The antenna is located between the watch face and the wrist strap. But once that GPS mode is turned on, you can keep track of your route, follow a pre-planned route that others are following, and save the route for later sharing.

This is the first monitor I’ve seen that includes a battery in the chest strap too, which Garmin refers to as the “heart rate monitor”). Also, the wrist device includes a rechargeable battery, another first for me.

If that black color doesn’t appeal to you, the Forerunner also comes in green.

Last, here’s a cool feature: You can race against a “Virtual Partner.” You set the specifics about how fast and far your partner is running and then try to keep up with or beat your competitor. Of course, at the end of the race, you’re the only one who can buy the beer; but then again, with a virtual partner, you’ll also be the only drinking it too.

The Axion Geo-632 is another of those GPS bargains that you can buy new for under $100. This device is designed to be used in a car or in “pedestrian mode.”

Like the Nextar P3 GPS, the Geo has a 3.5-inch screen. It also comes with the now-typical GPS features, such as 3D map view, a built-in MP3 player, a touchscreen, pre-loaded maps, automatic rerouting, and turn-by-turn directions. It also provides a picture viewer, so that your passengers can entertain themselves during long stretches of straightaway by viewing a slideshow of your most recent vacation.

The problem with an inexpensive device is that those typical features may not work in standard ways. For example, a reviewer on Amazon says that you can’t listen to MP3 tunes on this at the same time you’re using it as a GPS. There’s no jack for headphones either. You can’t adjust the volume control of the unit without exiting the GPS program first. And you can’t switch between night and day automatically. In other words, the interface for the Axion needs some redesign and you can expect a slightly painful learning curve.

Another Amazon reviewer complains that you can’t pick up satellites immediately when you turn the device on — that sometimes you’ll have to wait several minutes for synching to take place. She’s found a way around it, by plugging in her home address and clicking some buttons a few times, which speeds up the process.

Finally, that touchscreen actually requires you to use a stylus. (Evidence: See Figure 1.) Lose that and suddenly it becomes less useful at getting you around.

On the other hand, if you’re a walker like me, having a device that’s small enough to stuff in a pocket yet functional enough to work in the car means you don’t have to buy multiple products to find your way through the world. So, screwball interface, sorta-good features, and decent directions — you’ll have to decide for yourself whether it’s worth the hassle to save yourself some green. Sometimes it is.

When you go ultra-cheap on a GPS, what do you lose? That’s the question I’m going to tackle today and for the next few days. PriceGrabber includes 10 global positioning systems for vehicular use under $100 that are new (vs. resold).

The Nextar P3 GPS is one of these, and it actually gets a ranking of five stars from three reviewers. (No, that’s not exactly overwhelming, but it sure beats another product to which a lone reviewer gave a single star.)

This $99.99 device has one major difference from the other models I’ve written about recently. It has a smaller display — only 3.5 inches vs. seven. That means your eyesight better be up to snuff or you’ll need to adjust yourself to seeing less of the area you’re navigating through.

However, you will get the absolute basics, including a built-in speaker with voice-guided directions and turn-by-turn voice prompts; a pre-loaded state map for the United States; a database with 1.6 million points of interest; an address book that can store up to 300 addresses; a feature that will recalculate the route; a slot for plugging in an SD card; and 2D and 3D map viewing modes.

Review gnxtut from TN likes the “nice female voice” and the speed warning feature. Quince123 found it to be an “excellent product” with a very visible screen and “excellent text to voice,” which worked well even on the streets of Chicago, which anybody who has ever been there knows will be full of detours, construction sites and Oprah lovers.

Face it, in the arena of GPSs, if it finds you a signal and tells you where you are, then tells you how to get where you’re going next, who cares that it won’t show your photo collection?

Besides Garmin and HP, a few other companies sell GPS devices. Nextar offers a model that’s under $300. And the bonus with this model is that it includes a back-up camera. If you suffer Prius envy, maybe buying this would grant you some little consolation.

Here’s what the Nextar I4-BC offers:

• A 4.3-inch color display, just like the other units I wrote about.
• A built-in speaker.
• Voice-guided directions and text-to-speech.
• Built-in maps for the United States and Canada.
• 1.6 million points of interest, including hotels, restaurants, airports and the like.
• An address book that stores up to 300 addresses.
• Automatic recalculation of the route, for when you just plain change your mind.
• A speed alert.
• An SD card slot for additional memory.
• An MP3 player and picture viewer.
• 2D and 3D map viewing modes.
• A rechargeable battery.

And then there’s that back-up camera, which provides a view of what’s behind your vehicle, with a viewing range of up to seven feet. You’ll have to work some installation magic to get it attached to your license plate holder, involving cutting holes in metal and doing a bit of wiring work.

What you won’t get with the I4-BC is Bluetooth, which would allow you to handle calls through the GPS working in cooperation with some Bluetooth cellphones. Nor does it have a built-in FM transmitter or live traffic information. If that’s important, then pay the extra $100 or $200 for one of the other units.

To use this device — or any of the GPSs, I assume — you need to have a computer, from which to load the device with its maps and databases of Starbucks locations.

The Nextar offering packs a lot of functionality into a small package. Road trip, anybody?

Garmin calls its nuvi series of global positioning systems “Personal Travel Assistants,” which sounds like a concierge. And who doesn’t want a concierge — especially one you don’t have to tip?

The nuvi 760 GPS, which is fairly equivalently priced to the HP iPAQ 310, also includes a lot of the same functionality: pre-loaded maps, text-to-voice, an MP3 music player, Bluetooth and route planning. The screen is 4.3 inches diagonally, the same as with the HP model. It has a backlit display, a compass, speedometer, an odometer, a 3D map view, and a touchscreen.

It also has a few unique features that users really love or kinda hate.

The 760 lets you make hands-free calls through a built-in mic and speaker by pairing it with your compatible Bluetooth phone. You dial the number on the nuvi touchscreen keypad (always a tricky business while maneuvering through city traffic). To answer calls, you tap the screen and speak directly into the GPS unit.

An integrated FM TMC traffic receiver sends alerts about traffic delays and road construction to keep you nimble during commute. (Yes, this requires a separate subscription, but compared to the price of gas and the probable value of your time, it’s a bargain.)

You can buy optional SD cards to plug in that include language translations and additional travel guides.

Let’s find out what reviewers say.

stathis finds the software “fast and the touch-screen responsive. Very easy to configure. The display is bright and very visible. The Bluetooth works perfectly and instantly saw my cellphone.” But, the traffic report is slow to download — 10-plus minutes in Los Angeles. As this customer explains, “There are only two traffic colors: red and yellow. There is no green, hence you do not really know if no color means no data or no traffic. Still, some times you have no color, and think traffic must be OK, only to realize in a few miles that the color is now yellow.” That, says stathis, makes the traffic service sub-par.

fchange777 from CA bought the device for his wife and gives it five stars. But he also says that he’s experienced an echo trying to speak to somebody else through the GPS. For that reason, he’s also picked up an external mic from Garmin, which has addressed that problem.

login4k from VA wishes the map update included with the unit lasted more than two months. login advises patience when downloading and installing a new map, which was about two gigabytes in size. He or she also suggests buying a Garmin portable friction mount, which will be easier to remove than the windshield or fixed dash mounts, which are included in the package.

Gman757 from TX would prefer that the GPS made it easier to find places, such as restaurants. As he writes, “You can search by name or by category, but not both. For instance, if you want to find a restaurant, you can specify the type of restaurant only. It will list the restaurants of the specified type, in distance order. If you want to find a specific restaurant, you have to search by name, but it will list every single thing (gas station, restaurant, store, etc.) with that name.”

On the other hand, Gman likes how his GPS remembers where he parked.

My brother just introduced me to Motion Based, a web-based application that translates global positioning system (GPS) data into useful information and lets you share it with others. Only problem is, I need a GPS to record my various hikes and bike rides in the first place.

There are only about a thousand GPS systems available right now, so my options are somewhat limited. But, hey, I’ll see what I can do about whittling the list down to something manageable.

Today, I’m going to look at the HP iPAQ 310, which pegs itself as a “Travel Companion.” I like that. Makes it seem dog-like. You can customize your trip on your PC then download it to the iPAQ to keep you going in the right direction. (I’ve needed that more than once during my jaunts around California by bicycle.)

Maps are shown in 3D on a display that’s 4.3 inches diagonally. There are “millions” of preloaded points of interest, including restaurants and museums. The touch screen lets you slide the map around with your finger. Directions are supplied in spoken and on-screen formats. It’ll show you the geographic way to your Outlook contacts. There’s a handy world clock, for scheduling those US-Brazil-India phone meetings while on vacation. And you get a compass, a useful addition to a GPS, by all means.

Best, it’s more than just a GPS. This one provides you with entertainment too, including music, videos, games and photos.

Let’s see what the reviewers say about this one.

The overall consensus appears to be it’s a great value for the price ($265-$450), and the software that runs it is buggy.

As old_cotton from NY describes for its strengths, “Beautiful 800*480 high resolution LCD Screen; Built-in SDHC reader; MP3 Player; Bluetooth; WinCE 5.0 OS.”

But, says PGFan from CA, “The software hangs.”

Another common complaint is the low volume — especially a problem if you’re using text-to-speech and you want to hear directions. Says tableau from MA, “Even if you hear the instruction, you would not know what it is mumbling about.”

PGFan solved this problem, “by using an FM transmitter to listen to the music and directions through the car stereo.”

Next time, I’ll look at a system from the company everybody else wants to beat: Garmin.