I know a coupel of us have Iphones and seen this quite neat application. Yes it may be a bit micky mouse-ish but for £7 coudl provide some fun.
http://www.dynolicious.com/index-1.html
Performance Measurements
* 0-60 MPH
* Other Speed Tests (0-10 MPH through 0-100 MPH in 10MPH increments)
* Quarter Mile Elapsed Time
* Quarter Mile Trap Speed
* Elapsed Time and Trap Speed for standard intervals (60', 330', 1/8 Mi, 1000')
* Lateral G's (current and peak)
* Braking G's (current and peak)
* Wheel Horsepower
* Estimated Engine Horsepower
Results Presentation
* Realtime Speedometer and Graphs
* Realtime graphical skidpad display
* View results for latest test run or any saved run
* View averages based on vehicle, date, or modification
* Compare results between vehicles, dates, or before-and-after modifications
Configuration
* Rollout 0" to 24" (separate settings for 0-60 and Quarter Mile tests)
* Stores vehicle weight and drivetrain efficiency in your vehicle's profile
* Calibration routine gets the maximum accuracy possible with the built-in accelerometers
Accuracy
* A detailed accuracy analysis using professional timing equipment at a regulation dragstrip will be posted soon.