I've been using one of these for the last 6 months:
Amazon.com: Q-1000XT: Qstarz BT-Q1000XT Bluetooth Data Logger GPS Receiver (66 ch, 1-5Hz Update Rate, AGPS, 400,000 Waypoints, Vibration Sensor): Electronics
I've been meaning to write-up a review on it (I'd give it 5-stars), but haven't had the time yet. It works with everything I've tried to connect it to on the computer-side so far including Overland Navigator, TOPO!, and GPSgate. I never take a trip without it now.
The big pluses for me have been:
- charges its battery while sharing via USB
- LONG battery life
- LONG track memory
- extremely accurate, and gets a lock just about anywhere (including indoors)
- built-in track log (redundancy)
- easy to grab it and go on a hike for on-foot tracking (thanks to the built-in track log)
- geo-tagging photos after the trip