You don't want to really pick on someone that you genuinely like. In terms of 'Billy on the Street,' there are certain actors - I don't care if they find out because I do feel that way. Though it's almost never about appearance or something out of their control. I pick on choices they've made or roles they've taken.
I did a live late-night talk show called 'Creation Nation' with friends of mine. I had a sidekick and a band, and I wrote the whole thing. And it had the form of a late-night talk show, but we did it on stage because no one was giving me a TV show at the time.