Lumi reminded me that today is Pirate's Day. If you haven't already, go to a major city and talk to one of the various pirate NPCs to get a costume. For the easiest 10 achievement points you'll ever make, head down to Booty Bay and make your way to the Horde flight point (take the exit near the head goblin of Booty Bay) and jump across to the roof where all the Dread Pirates are. Then, talk to the woman and you'll get an option to drink with her for 10 achievement points and a pirate costume for 12 hours.
(Tips lifted shamelessly from WoW head.)