When we caught up with Karen O at the New Yorker Festival party over the weekend, we asked about her plans for Halloween. "You know how all these tortured indie-rock guys always wanted to date the cheerleader? Well, this time, I'm going to be a cheerleader, because I'm one of those tortured indie girls," she told us. "And my boyfriend is going to be the quarterback, and he's British, so he doesn't even know what that means." See more in our Party Lines slideshow.