Just got a 3G (upgraded from the 2G) yesterday and downloaded Track Day. Have a track event in 2 weeks @ SOW and will use this app and see how good it is. Will be using a transponder also for timing so I can compare the two. We will see if it was worth the $11.99
GPS Lite worked great last night on my evening lumber ( read as lineman running
) and it was a free app. May buy the full version for $2.99
Several other apps have already been mentioned that are great. Had a recent trip to Oregon and had downloaded a bunch of shows for my 4-1/2 year old. Worked out great on the plane.