The BBC currently have a great website up that allows you to play with interactive art in their studios. The BBC Blast Studios connects you to a live stream of the BBC studio (available 12pm-12am) where they have 3 interactive art pieces. Online users can choose an art piece to play with and then follow the instructions to participate.
My favorite is Mark, which gives you three paint gun shots at a large canvas. It is accompanied by a dragable timeline which allows you to see the artwork being created over time.
Fantastic idea. The combination of online visitors with real participatory art exhibits is almost too good to be true. This experiment in creativity will be available until June 9th.