Heidi Montag swung by Late Night with David Letterman last night to dish on all things Hills. Looking like a Playboy Bunny’s birthday cake, Montag gave Dave some insider scoop, broke down the real reason behind the Lauren-Heidi fued-that-will-not-die, and made some suggestions for how LC could better spend her time than criticizing other people and their boyfriends. “I think she should focus on her own life for a minute… try to get her own boyfriend.”