I like my handhelf GPS. It came with a serial adapter (though my wardriving lappy had only USB so I dropped $40!!!! for a radioshack usb->serial adapter) but being a hand-held, it's more practical for me, and its water resistant and because it's coated in rubber, I can wedge it up between my dash and wind shield, witch gives me a sort of HUD. It can show current speed and direction and has a real nice trip-data recorder, thins like max speed, average speed, average speed not including time spent at 0mph, distance, time spent at 0mph, and other useless but fun things
Garmin eTrex Legend $170 at Best Buy (I got a $30 rebate) The onboard map stinks for all but MAJOR highways (I live on a pretty major state route and it shows the road ending in the next town, which it does not.) The software to add more mapes is $300. But hey, thats what Map Point is for.