Last night on The Late Show, Dave Letterman had the calm and cool Brian Williams so flummoxed that he wished he was dreaming up the whole interview. But Letterman still proceeded to share his thoughts on the Matt Lauer - Ann Curry Today Show fallout. "It was crazy so NBC said, 'We gotta put an end to this because it's the Today show.' So now they come up with these crazy stories about the other end of the programming day, the Tonight Show." Meanwhile, Brian Williams blinked, grimaced, drank some water, and uttered an "Oh, good Lord." Then Letterman asked for confirmation — "Now, if I'm onto something, blink twice" — and Williams restored his serious face. Plus: Kid Cudi performed "Immortal" off of his latest album Indicud, due out April 23. Why he decided to debut an a cappella version of "Mad Solar" on the live set is unclear. (The recorded album, however, might make for a more, uh, mellifluous listen.) Also, Chris Hardwick and Jimmy Fallon dueled with lightsabers, and Vanessa Hudgens confessed she takes beauty tips (literally) from Rihanna. Watch our compilation to see what you missed.