OpenStreetMap
I took a bike ride from Rockridge BART and around Briones Regional Park and made some edits while on the move with http://code.google.com/p/osmeditor4android . There are a few small bugs but it mostly worked and is much easier than making notes and fixing things at home. I could do with getting a larger battery for my G1, it lasted about 4h using 2G data only.
Discussion
Comment from Andrew Chadwick on 7 April 2009 at 12:28
Strongly considering getting an HTC Magic (G2, ish) when they come out in the UK, partly because I want to get tinkering with Vespucci. How well does Android shape up for more traditional GPX tracklogging and photo-mapping, OOI?
Being able to edit data directly when on the move is really neat. I enjoy fiddling with Osm2go way too much. Now we just need editors for iPhones and WinCE kit so the orange-sunglasses and pointy-hair crowds can get mapping too ^^
Comment from Tom Brown on 7 April 2009 at 15:38
I'm frequently taking pictures without stopping on my bike. I can do this easily with Canon Digital ELPH series cameras but with screen lock, small shutter button and much lower shutter speed I haven't tried very hard with the G1. Garmin eTrex works great for GPX because the batteries last >20h and pack two more AAs for a second 20h. Also I don't need a network to see the OSM data (with maplint errors highlighted).