Punching speed

Does anyone know the different ways to measure punching speed?
I want to measure the force of my punch, one way is to use a high speed video camera (500 frames a second).
Can anyone think of another way?

Try checking this:

http://www.phidgets.com/index.php?name=PNphpBB2&file=viewtopic&p=1230&

Thank you, thanks a great link.
I found some software called videopoint which has been used previously in this type of experiment but it really needs a fast frame rate camera. Someone suggested that it is possible to use a punch bag and measure the swing of the bag after impact, but im not sure of the calculations on that one.

Thanks

Steve