Conan O’Brien performed at the Gibson Amphitheatre over the weekend, just a short walk from his former "Tonight Show" studios.

MTV News was there and wrote this: "This is my first time back at Universal Studios since I lost my job," O’Brien announced to the sold-out crowd, causing the Conan-crazy fans to boo his former employer, NBC. "Don’t boo too loudly. If you listen very carefully, you can hear bad ideas being green-lit."

Some of Conan’s special guests included "Mad Men’s" Jon Hamm and Jim Carrey.