It can be more subtle -- take Christian Bale's apology for being an asshole on the set of Terminator Salvation. He let everyone know he's "not comfortable" and "doesn't know how to handle" being a movie star -- he's a big doofus, just like us!
He has yet to apologize for the movie itself, though.
Jonah Hill apparently paid close attention to these lessons. After he decided to throw a homophobic slur at a paparazzo (instead of going the noble route and giving him the finger), he started his apology by saying he's been a gay rights activist "from the day I was born," followed by a recap of how that paparazzo was hounding him. By the end, he even managed to throw in a good "I am not good at being a famous person" -- it was beautiful, and it's been recognized as one of the most honest celebrity apologies ever. Bravo, Jonah.