Thanks Lidberg for hosting!!
I got this idea after seeing some physics class use the wiimote in some kinda pendulum experiment.Why not use the wiimote's built in 3-axis accelerometers to measue g-forces, acceleration and even calculate my own 0-60mph times!
So I did. I wrote a script to dump all the g-force readings from the wiimote to a comma separated value file, then did some post processing in MS Excel, and voila, I can see every bump, every curve, my acceleration and braking, and even calculated my current speed using high school physics (v=a*t) I even convinced my coworker to take me out in his E46 M3 to measure his SMG's performance

I admit, it's not super accurate since the wiimote spits out G readings rounded to two decimal places. It also provides other acceleration readings in finer granularity, but I couldn't figure out what metric it was recording in. I used Gs since I knew it was just the acceleration of gravity (9.8 m/s/s).
Here's a copy of the script that dumps everything out to output.txt
All you need is Glovepie v0.29, a Bluetooth dongle with BlueSoleil, the Human Interface Device drivers, and a standalone wii remote!<br>All the basic instructions on how to get your wii remote connected to your PC can be found here:
http://www.wiili.org/GlovePIE
If anybody wants my excel spreadsheet with the formulas and graphs, you can find it here:
ttp://www.christiancarlson.com/klee/sample_wiimote_speed_calcs.xls