I've tried the IpBike app over my last two commutes. I like it. I'd start with that one first to see how you feel about it (it's got full features for a limited time vs. cyclemeter which has very limited features in the free version).

The two apps are similar. What I like about IpBike is the following:
1. Can customize the screen layout more
2. Has an "auto start" feature that goes on after you ride a certain distance with the sensors on. This means I don't have to take my winter gloves off to start recording my ride.
3. The auto-pause is quicker to react.
4. Has the option to dim, but leave on, the screen after a while which saves battery.