To those with GPS experience.

I saw oldsouth uses his E-MAP GPS to measure accurate speeds, etc.

On another auto list, I read a guy who had a bad speedometer/odometer and the dealer wanted $400 to fix it. He eventually bought a GPS and mounted it where the speedo is on the car and used it that way.

I am thinking about getting a GPS (having no prior experience). My main reason is that I can monitor the speed, trip mileage, stuffs like that. A mapping (with pre-loaded map) is a plus, a rechargeable battery (or an included car adaptor) would really be nice.

Any thoughts and suggestions?

TIA.