I would conquer Fox News, and I'd kick Bill O'Riley into a hole when he called me a pinhead.
Alt: Replace Fox News with Vatican City, and replace Bill O'Riley with the Pope.
Either that, or I would whore them out to the UFC and make millions off of the side bets.
EDIT: And that's another thing. Did King Leonidas count as one of the 300 Spartans, or was it King Leonidas + 300 Spartans = 301 Spartans?
EDIT x2: Some more things to do with 300 Spartans.
Drive Chippendales out of business.
Open a moving service.
GET LAID 300 TIMES! (Because you didn't say they couldn't be Spartan WOMEN).