I bought the DeLorme Earthmate GPS which came with Street Atlas USA software, and used it with a laptop on vacation. Worked great. I hated the Street Atlas software (worst user interface of all time) and ended up using Microsoft Streets & Trips instead after hacking the 15 second updates down to 2 seconds.
A lot of people seem to like Street Atlas because it gives voice commands for turns, but I didn't care about that. I was going through Wyoming/Colorado/Montana/Utah/Arizona and just wanted to know roughly where I was, how far to the next town, etc.
I was very happy using the combo of the Earthmate GPS with Streets & Trips.