If you're still at Cal then you should talk to international house, they would know lots of good visa consultants etc -- but on the other hand they have to play by the book as they could jeopardize their entire visa sponsorship programme if they do anything wrong... so you won't learn any dirty tricks from them. But maybe you could get work as a tutor etc which would let you stay in the country..?
One of the things required for the H1B is a Labor Certification Application (LCA) where the employer has to demonstrate that they have tried to find americans who could fulfill any position offered, and failed. Unless you're tutoring in a very specialized area, its unlikely they could do that.
If you're at UCB then perhaps you can frame your startup as a spinoff company, which universities love. You'd be trading capital for a visa.
That's the best idea I have right now.
Otherwise there's always 20% time at google.