In suburban Boston, opera singer Beth Grzegorzweski often drives to rehearsals alone at night and wants to feel safe.
"I find a GPS is best to get me home safely, especially in unfamiliar areas," she said.
Three months after spending $450 on her GPS, she found her car window broken, and the GPS gone.
"We had left the GPS unit inside the glove box that night, and the landlord downstairs heard the window smashed in," Grzegorzweski said.
Thieves in Jersey City, N.J., were busted when undercover cops discovered dozens of stolen GPS's being sold in the back of a clothing store - bought for a fraction of the cost and resold, according to Jersey City Police Sgt. Wally Wolfe.
The number of GPS thefts reported to police has quadrupled in just the last two years, from Boston (1,611 in 2007, up from 217 the year before), Houston (1,303 in 2007) and Denver (rising from 25 in 2006 to a projected 100 this year). Elsewhere, the number of thefts in Nassau County, New York, spiked from 130 last year to a projected 2,155 in 2008.
Outside Washington, D.C., police in Montogomery County, Md., saw more than 500 car break-ins in February alone. The main reason, they say: GPS thefts.
"The bad guys are breaking into the cars just 'cause they see this," said Lt. Frank Canella, North Bergen, N.J. Police.
His advice: Don't leave it exposed. "They don't have to see the whole thing," he said. "You need to remove the cradle unit - don't leave that on the windshield of your car, you need to take this out of your car - don't put this under your seat."
Obviously leaving a GPS on a windshield is asking for trouble. But police say another way to keep thieves from targeting your car is to make sure when you take the GPS out, wipe off the circle the suction cups leave behind.
The FBI says at least 29,000 GPS's were stolen over the past two years, but that's considered a fraction of the total, because it counts them only when the owner can provide police with the item's serial number.
"In most cases, without a serial number, you have no chance of ever seeing your GPS again," said Massachusetts police officer Tom Shea, founder of juststolen.net.
Shea started the Web site to help people register and find their devices. He says leaving your GPS in the car is like leaving a $100 bill in plain sight.
"I think most people just can't be bothered with the aggravation when they're running into the store for five minutes," said Shea, who warned, "Five minutes is all it takes."
In Portland, Oregon, Ken Westin last year started gadgettrak.com, which installs software in your GPS and other devices (like a digital camera or iPod) to help catch a thief. When a programmed device is connected to any computer, their database checks to see if it has ever been reported stolen.
"If it has been reported stolen, it's going to gather information from that host system, such as the user name, the computer name, location information," Weston tells CBS News. "If you want to update your maps, you have to go in and plug that into a computer - and that's when we can catch thieves."
The fee is $12.95 to register one device, $19.95 for five. Gadget Track will give their information to police.
"We're trying to find ways of working with law enforcement as well as pawn shops so that on the back end we can create ways for pawn shops and things like that to look up these devices to make sure they're not stolen," Weston says.
GPS manufacturers like Garmin and TomTom are trying to make their products less tempting to steal. New models now require you to enter a 4-digit pin number to work, the hope being if thieves know they can't use it, maybe they won't steal it.