AskMen offers some interesting advice, especially:

Drink olive oil: This is an old Mediterranean remedy and it works on the same theory as eating fatty foods. Personally, I’d rather eat dinner than swallow a spoonful of olive oil, but if there’s any truth to this theory, I suggest you dip some bread in olive oil rather than slather it with butter (if nothing else, most doctors would agree that your heart will thank you).

How To: Prevent Hangovers [AskMen]