Have you given thought to issues with legal liability that your prospective startup would get themselves into should they take you on board?
Thanks for raising this issue, I hadn't considered it before.
http://work.ocregister.com/2010/04/05/working-for-free-unpai...
Another way to do this would be to structure it as a contractor to be paid $100/week for general consulting; something that insulates your friendly employer from any risk with bringing you on board.