For all iPhone and iPod Touch owners, BMW has a nice nifty surprise for you: BMW M Power Meter. With this little tool, you can measure the speed, acceleration in the longitudinal and transverse directions, the time for traversing a particular route or map to achieve a certain speed.
Even if the app is branded by BMW M, it certainly works with all other vehicles as well. For those of you looking to customize the application even more, BMW offers three free design skins that you can set the app to your own taste.
A similar application was launched by Dynolicious in 2008 which uses uses the accelerometer built in to your device to sense the motion of your vehicle and to measure the performance characteristics of your car.
The BMW M Power Meter can be downloaded through the following links: