Originally Posted by Bigwave

I hope that was a joke

You don't need anything too crazy, and accuracy can be +\- 5 or so degrees with no problem at all, it's just to get an idea really.

Lots of guys around here (Myself included) use this Trakpower

http://www.towerhobbies.com/products.../tkpp9000.html

Not too big and has a lanyard\stopwatch for your pit guy to keep track of fuel stops etc.