Some ideas for Justin.tv:
* allow viewers to control imaginary friends who can interact with Justin; only he and the viewers would be able to see and hear them.
* have one channel that gives the most interesting video among all other channels in (near) real-time based on user feedback (e.g., in the chat rooms)
* a search engine for clips based on associated chat text; yes, the chat is pretty noisy data but I think you will get interesting results anyway
* imagine using justin.tv to augment your mind, taking advantage of the intelligence and knowledge of your viewers
* use justin.tv as a way to interview people for jobs
* when Justin meets someone for the first time, viewers can show flashbacks from Justin's life to give a first impression (and the choice of flashbacks would depend on the person he is meeting for the first time)
* have a prediction market about all sorts of short-term events (e.g., in the next day/week) in Justin's life