New Microcontroller Zapper project

I have made a cheap 12v Zapper, based on a microcontroller.
Check out the project page: http://groups.google.com/group/uzapper


I didn't find any Zapper plans on Google that was based on a microcontroller, so I went looking for a cheap way to do it.
Since I spent some time putting this together, I thought maybe somebody would like to benefit from my efforts.

I'm not an electronics engineer, so there is certainly some room for improvement in the circuit.

The Zapper can run on 9v as well. Remove the protection diode and change the voltage monitor levels.

I don't know much about the theory behind the Zapper, but for me it has removed an aching spot in my back. Well if I keep zapping once a week that is. So I haven't found the underlying cause.