I dropped mine a while back whilst falling in the icy snow. It pissed me off because not only did I drop it looking like an idiot, but I also dented the corner pretty bad.
I took it into the Apple store, politely asked them to replace it because it had locked up a few times even after a format (which technically it did do once) and they replaced it without an issue.
I have found that if you are nice and approach them with respect, they usually take care of you.