uh... bootleg liquor? That was the most profitable industry during the depression. Don't think that will work so well anymore. Apparently growing marijuana is a fast-growing industry now thanks to the recession though.
More seriously, here are what seem to be the main careers that use physics now:
Programming liquid flow models for the oil/gas industry: Current projections are that we'll warm the earth up 10 degree C this century, but I'm sure with enough physics nerds working on the problem we'll be able to get up to at least 15 degrees C!
Programming bomb models for the military: We need a way to kill as many Iranian children as possible for the minimum cost, and someone needs to program all those smart bombs. Better a pure nerd than someone who might have accidentally taken an ethics class.
Programming finance models: I guess that's your job now? There's still a few unions that have managed to protect their pension funds, and still a few middle-class families that own a home. I'm sure if enough nerds work on this problem you'll find a way to transfer their all their wealth into the hands of rich bankers.