LETTERMAN: Jonah Hill Has 'Day Terrors'

Jonah Hill tells Dave why you don't want to sit next to someone who has "night terrors" on a plane.

If Bart Simpson Were a Real British Man

Mat Williams, a London-based artist puts on his man-sized Bart Simpson costume and writes out every Simpsons blackboard gag.

Newt Gingrich Equates Obama and Hitler

Someone's been watching too much Glenn Beck. I guess that's one way to sell books.

IMPROV EVERYWHERE: Ghostbusters!

Of course, Improv Everywhere recreated Ghostbusters at the New York Public Library.

Preview: Mitchell Hurwitz's 'Running Wilde'

Here's a first look at the new Fox sitcom from Mitchell Hurwitz, starring Will Arnett and Keri Russell. What do you think, is this the second coming of Arrested Development, or not so much?

Conan's 5 Favorite YouTube Videos

In honor of YouTube's fifth birthday, Conan O'Brien presents his five favorite YouTube videos. You can watch his picks here.

LENO: Bill Cosby Does Stand-up About Being Old

Bill Cosby performed his unique brand of sit-down stand-up last night on Leno. Glad to see he's still drawing on his experience with some brand new material about the peculiar behavior of old people. Don't worry, this clip is almost entirely Jay Leno-free.