I saw it a few years ago, so I can't really remember all the details. I do remember thinking it was really funny, although I didn't understand a word Brad Pitt's character said.
You should check out "Lock, Stock and Two Smoking Barrels" which is an even better movie done by the same director (I believe it's Guy Ritchie, Madonna's husband). Different characters, different plot, but it does involve money, scams, and same kind of hapless losers who manage to get themselves into trouble. Hilarious.