-tech boom: internet bubble 2.0 has been getting frothy in silicon valley for a while now. VCs were giving money to some ridiculous ideas. Might be too late now.

-real estate flipping: recovery means real estate is doing pretty well. Northern california has a lot of buyers from china coming in and paying 50% over asking... cash. This one is pretty risky though and you'd need to know contractors that you'd trust to be able to buy a fixer and flip it.

-fracking/oil: don't know anything about this, but there's money there. might be tied up by the big players, though.

-wall st.: I've had some peripheral experience here... I used to write trading software and I worked at an investment bank. key here is to get as close to the trading as possible, or as close to the deal making as possible. Avoid back-office shit.

Any other ideas? Stuff overseas, maybe? I think there is almost always some sort of boom happening somewhere.

One interesting thing I read someplace - most of the people that did well at all during the 1849 california gold rush were not the prospectors, but people that sold goods and services to the prospectors. Most of the prospectors never made or kept much of anything.