With the feds seizing pokerstars, full-tilt poker, and absolute poker Alternative modes of gambling will surely be on many's mind.
Bitcoin and gambling are a natural fit.
Play poker with bitcoins. Apparantly, the industry standard rake is 5%. With bitcoins, it's 1%
You can also do sports betting with bitcoin.
Then there's the BitCoin lottery. It's currently down for (among other reasons, including a bug) not having many players. I take this as evidence of bitcoin user's intelligence.
Oh, and if bitcoin weren't easy enough, now there's instawallet
EDIT: You can also play roulette with bitcoins