gps and linux?

["Matt Price" <moptop99@gmail.com>]

hi,

i'm about to take off on a long road trip through the us and am
planning the technological elements.  I'm looking for advice on
purchasing a gps unit.  If possible, i'd love to get something that
ran Free software, or was at least intercompatible with my debian &
ubuntu based machines.  we will probably have a laptop hooked up for
watching video/playing music, and could either run a gps card off of
that laptop or have a standalone unit, whichever seems to be a better
idea.  the set up has to be usable not just by me but by my nongeek
family members.  has anyone done this/have a suggestion?

thanks as always,

matt