Yeah Yeah Yeahs perform on Conan O'Brien

Last night was worth staying up late to watch the Yeah Yeah Yeahs perform live on the otherwise moribund Tonight Show.

There are two things fascinating about seeing Karen O in action: The fact that she can replicate the yelps from the studio, and her bizarre, intepretive dances.

This clip also features the ugliest outfit I've seen on a lead singer since Steven Tyler quit coke.