GPS devices for attaching to a dog’s collar include the Zoombak, left, and the Pocketfinder. They both work to track a wandering pooch, but both have drawbacks.

Los Angeles Times / MYUNG J. CHUN

How do you know when a dog is a geek?

When he’s wearing the latest in doggy hi-tech bling, a Global Positioning System locater.

The satellite-linked devices, which have found their way to cars, big rigs, boats and even bicycles, are now available for the canine set.

Two companies are making collar-attached models that send a warning if a dog leaves its designated area. The gizmo then gives the animal’s location, allowing you to find it without driving endlessly around the neighborhood, shouting its name.

In theory, it’s a cool idea. In practice, neither of the devices — Pocketfinder or Zoombak — is quite ready for puppy prime time. And both are rather expensive because of monthly fees.

But as anyone who has lost a dog can tell you, it’s an intriguing use of digital tech.

Here’s a look at the two products, based on real-life dog tests.

Pocketfinder

Location Based Technologies is taking orders for its product, which is in the final stages of development. Executives at the Anaheim, Calif., company say they’ll start shipping it this summer.

But here’s hoping that they’ll wait until the bugs are ironed out. Based on the prototype that was tested, Pocketfinder is potentially an exceptionally cool gadget.

It works this way:

The owner activates the device, which is attached to the pet’s collar, via Pocketfinder’s Web site. This allows it to be digitally located, a trick it accomplishes not only through the global positioning system but also with use of the cell-phone network.

The next step is setting a geographical boundary — the area you want your unaccompanied dog to stay within. That could be a backyard or a field.

This was where the product really shines. To set the boundary, you use clearly marked aerial photo maps from Microsoft’s excellent Virtual Earth platform.

For example, I was able to pinpoint my backyard, which is not at all spacious. Then I designated the yard as a “safety zone.”

As long as the device was active, I got a cell-phone text message and e-mail whenever my dog Earl left the yard.

However, this brought up a problem. I didn’t get the message until Earl was out of the yard for about four or five minutes. That amount of time can be crucial if you live near busy streets.

When you get the warning, you can locate your dog on the site map. But in the test, the map could be refreshed only once every five minutes. That can make for a nerve-racking delay.

(Ideally, when looking for the dog, one person would be stationed at the computer to direct the search. Or if you have a cell phone that clearly shows the Web site map, you can do it yourself.)

By the time the product is released, users will be able to shorten the refresh time to about a minute, Pocketfinder said.A more minor and easily fixable problem was that the instructions for using the Web site tools were a bit confusing.

The prototype device was bulky, but that will be fixed, Pocketfinder said. The device, when released, will be a thin disk about 2 inches in diameter.

The device will cost about $130, plus $15 a month for the service.

Zoombak

This system, from Zoombak in New York, works in a similar fashion.

But it has one distinct advantage — when trying to find a dog, the device can be refreshed manually to give a location that’s only a few seconds old.

Here’s how it worked in testing. I was out with Earl, who was wearing the Zoombak device on his collar, while a friend searched for us from the company site. All my friend had to do was hit the “Locate” button on the site and within a few seconds he would get a map showing where we were.

But Zoombak has disadvantages, starting with the device itself. It was about the size of a hotel soap bar but a good deal thicker.

That made it bulky for everyday use on a dog. At a local dog park, the case holding the Zoombak got dirty in just one trip as Earl played with his buddies.

The locater maps were primitive in comparison with Pocketfinder’s. There were no aerial pictures, and some major streets were not named. When I asked my friend monitoring the site where I was at one point during the testing, all he could say was, “a big beige line.”

Zoombak is more expensive. The price listed on the site is $200, plus a $15 monthly service fee.