The Baltimore Sun has a story today about the increasing theft of portable navigation systems, as well as satellite radios and other portable electronics, from people's cars. In Anne Arundel County, Maryland, police found 33 stolen GPS units in local pawn shops, citing that these $200-to-$1,000 tech gadgets are good for a quick $150. The thefts are occurring nationwide, and police say it's not enough to hide your device in the glove compartment. Windshield and dashboard mounts are dead giveaways that you have such electronics in the car. I'm curious; for all the GPS owners out there, what do you do with your portable nav system when you leave the car?