I've been trying to get eclipse to install ADT, and that hasn't been successful yet. That is another problem for another thread though. The only app I've been really wanting and was going to write is a logger / lap timer. The simple version would be to log all of the GPS and accelerometer to the SD card. From that base, then set a start/finish point with the GPS and calculate lap times based off of that point. A more advanced (future) approach would be to set the start/stop point through the UI, draw the map on the screen, show current location, current accelerations, current time on the current lap, previous fast lap, and potentially predicted lap times. The intended application is automotive, but I've heard requests for similar applications (GPS only) from runners and bicyclists.