Pogue: A Voice to Guide You on the Road

G.P.S. didn’t always stand for Global Positioning System, you know.

In the beginning, it stood for the Grunting and Pointing System, used by cave men to indicate the nearest watering hole. By the horse-and-buggy era, G.P.S. had evolved into a different navigation technology: Guidance by Pony Sense.

Rusty Kennedy / AP

In the automobile age, G.P.S. came to mean Grumbling by Peeved Spouse. ("Why won’t you just stop and ask?")

Today, G.P.S. is a beautiful thing. A receiver in your car can learn its own location from 24 government-owned satellites overhead — your tax dollars at work.

You're guided to a destination with colorful moving maps on a touch screen and an authoritative voice ("In 200 feet, turn right").

I went looking for G.P.S. models that fulfill three requirements. First, each must be tiny (about the size of an index card), self-contained and battery-operated, so you can take it hiking or biking when it’s not plugged into your car’s cigarette lighter.

Second, each must display live traffic and accident data — and offer to reroute you as necessary. (The traffic data is available mainly in big cities and on highways, and costs extra — usually $50 to $80 a year.)

And finally, each must pronounce actual street names — not just "Turn right," but "Turn right on South Maple Street." That feature makes an enormous difference when you're flying blind in a new town.

As it turns out, only the top models meet those criteria.

Each also plays music and photos; makes wireless connections to Bluetooth cellphones for hands-free calls; and offers a built-in database of United States and Canadian roads stored in memory. (Units that keep the data on hard drives are slower, more fragile and more power-hungry.)

Each receiver also knows about millions of points of interest: restaurants, cash machines, gas stations, parks, hospitals and so on. Most let you call one of these places (through a Bluetooth phone) with one tap.

Now, even these top-of-the-line units are imperfect; in a world where roads are constantly changing, a G.P.S. receiver is only as good as its most recent database update. But in general, these are absolutely incredible machines.