Got my first bike in years. I just decided to give it a bike supercomputer. The main ingredient was my iPhone4, an iPhone 4 holder and the cyclemeter app. UPDATE: This cheap holder can break. Don’t buy the cheapest type. The app will give you a dashboard with current speed, average speed, ride time and more. You can compare different rides and share it. It can tell you this trough voice too. It can be operated with one hand, perhaps only your thumb. Really practical trip tool with the combination of the google maps app and a nice music player like Wimp.