In the U-2, when "on the road", most of us fly with 3-4 handhelds. Sounds like overkill, but each serves a specific purpose.
The one we use for "normal ops", and just plain navigatin' and SA is a Garmin 196. We've got some new ones, and I think they are Garmin 96C (I haven't used them).
Locally, I fly with a Garmin GPS III; old, but very effective.
Our unit bought a few, and we sign them out when needed.
We will put them in with the trainees when they go solo, and then download the plot when they return, allowing us (the IP's) to see exactly how their flight progressed. Yes, you can bust a ride based on your HHGPS plot.
They're great in the T-38, especially when VFR. Keep your destination's range in the HHGPS, and you can constantly work your Bingo and maximize your playtime.
[ 17. February 2006, 02:17: Message edited by: Huggyu2 ]