I just have a cheap Android phone and the free Strava app, and I must say it's pretty cool. Once I figured out how to lock the phone while recording a ride, it has worked great. The bonus is that when I finish my rides, a cyclist/racer friend often gives me kudos and comments. The social networking aspect is cool so far. Also, seeing the stats on the segments gives me a sense of how a 'real' cyclist performs on the same routes I ride and encourages me to want to push myself.