I've always thought that you could make a fair bit of money betting on football matches where one team is at least two goals up with only a few minutes to go. You still get a payout of 1%, and it's a near-certain bet. If you're willing to risk a decent chunk of money and add a few sanity checks (never bet on Arsenal if Manuel Almunia is in goal), it could be some nice income. One percent a couple times per week.

I have to actually figure out one of these betting site APIs and try to do it some day.