Sony do a GPS product called Street Navigator (or something similar) for about £150.
Its a GPS built into a PCMCIA card that hooks in your laptop and comes complete with road navigation software ("Turn right at the next junction" type of voice thing). Cheaper than paying £1500+ for a car sat-nav system!!
Good thing is you can run the aviation software on your laptop as well and take the input from the GPS.
Only problem for me was a). vaio screens aren't much good in direct sunlight, b). there's no where in an R22 to really put a laptop...
