One of the best things in comedy is when someone invents a new joke. I'm not talking about a traditional, set-up/punchline gag, what I mean is a totally new way of being funny. The charmingly insane US comedians Tim Heidecker and Eric Wareheim do it a lot.
For example, during last year's promotional armageddon for Shrek the Third (I remember seeing a bottle of Shrek bleach in Sainsbury's), they made a series of YouTube commercials enthusiastically endorsing the new movie, giving testimonials, even demonstrating the official website. They were so believable that some of their fans cried "Sellouts!", not realising it was a super-sarcastic joke (which they pulled off without being mean-spirited or smug). Their psychedelic, hyperkinetic, idiotic, joyously funny show looks like all TV will in 100 years' time.
Peter Serafinowicz is supporting the ICA in its 60th anniversary fund-raising campaign, in association with SpinVox