I'm using a PalmOne GPS receiver with a Sony TG50 PDA as my primary tracklog recorder.
For many years, I have used a Garmin GPS II Plus for navigation, but that's set to the OSGB datum and I haven't yet attempted to convert my old recorded tracks to OSM's WGS84 datum.
In the past, I have also used a DConnex-branded GPS mouse together with a laptop (running Linux and GPSDrive).
My map contributions are edited using JOSM on Linux (Fedora Core 6).
I have a background in parallel and distributed computing, which might come in handy in this community. My primary programming languages are Java, C and Perl.