If its for a 'non-primary' purpose then have a look at any PDA with a bluetooth facility, a bluetooth GPS bug and the software from 'www.pocketfms.com' which is free to download and use and is IMHO excellent!
Full trip recording, aircraft performance, airspace warning, DAFIF navigation cycle AIDs updates, weather download, route planning with automatic terrain and airspace avoidance, hide/show capable airfields, radio frequencies, NOTAMS, next airspace contact freqs, TOC/TOD arrows, auto VFR approach planning and a worldwide database of obstacles plus a stack of other things including the ability to overlay your own approach plate scans onto the moving map!
(Have used it from the front of an Airbus and works brilliantly)
This enables you to have a full PDA, Car nav system (Tomtom) and an entertainment system all in one. This combo saved my bacon a couple of times in America
Cheers
W2P