Last night on the Late Show, Will Smith displayed a major symptom of the rap "bug" he'd apparently caught from Kanye West. The band played Smith's own "Summertime" as his walk-out song, but instead of leaving it at that, he rapped along, unmiked at first until he grabbed the microphone for a full-on ode to summer time. Plus: Mary Lynn Rajskub denied any intel on her casting in the new 24 miniseries, but she disclosed what she'd really been typing the whole time Chloe looked so diligently ambidextrous at her computer. I was "typing affirmations to myself," she told Conan. Things like, "Don't take Kiefer's intensity so personally. He's just acting" or "You look really pretty today, Mary Lynn." If only we could see her faking it once again. Also, in a nod to the rest of last night's awesome musical performances, Jaden Smith rapped "The Coolest," but the cutest happened when Jimmy Fallon tried to mike-bomb him; and Kelly Rowland and The-Dream sang "Where Have You Been," but Kelly's white leggings might have been the real attention grabber. Watch our compilation to see what you missed.