I want a GPS system for the Car, Sailing and Flying. However when I fly and sail I tend navigate with paper charts so I want a GPS system as a secondary system, but would also like a plotter / moving map display. I have decided to get a HP Ipaq (2210) with either a bluetooth GPS or compact flash GPS, but any NMEA GPS input will work. Memory-Map do some good software with OS maps, Maptech Marine Charts, and CAA aviation Charts. Tom-Tom navigator do a good routing / navigation software for the car.
The whole lot ain't cheap, but its modular, you can buy as much or as little as the software as you require, plus you still have an ipaq pocket pc for other stuff (logbooks, diaries etc.)
I got a Garmin GPS 12 hand held - a very basic unit - which I use with road maps for the car and with charts in the boat.
Its brilliant, and using Multimap website its possible to get a grid ref for virtually any address.
Personally I can`t see the need for moving map displays etc. afterall you`re ment to plot your position regularly and not totally rely on technology - too much technojoy will lead to too much reliance on it.
You can see the address from my 'signature' at bottom of this post ..... in the group we have marine / aviation / trekkers / car users ....... so someone will help you.
Look at the Garmin 276C, this is designed for car and boat and will give you spoken directions in the car with the added road navigation pack. I have a Streetpilot for the road and it is excellent, wish this product had been available when I bought my boat plotter.