Even though I really like the Nike+ system (not the iphone app, but the receiver and shoe sensor), you can't really use it for non-running activities, like biking or hiking.
This is one of my favorite trainer/working out apps. Its free on Android phones, there is also a paid version too, but the free one does a lot already, and I'm all about free apps.
Cardio Trainer is really great for running, biking, hiking, anything. I think the photos will explain more than I can with words. Really easy to use, and my favorite features are that it will pause on its own when it senses you not moving, so if you stop longer than a second (or any time you set it) it will pause, and resume once you start again.Great for stoplights when your running and biking. Also it gives a good breakdown of your stats, speed, elevation, etc.
Here are a few photos
Graph of your speed.. I can't figure out how to rotate pictures.. so turn your head to the right :)