Film: Exit through the Gift Shop

Everything the poster says is true: Joyous, Inventive and Funny as Hell

Banksy himself “appears” in the film cloaked in a hoodie, with his voice disguised.

From the trailer - very clever. :-)

Last Sunday I saw Exit through the Gift Shop: a documentary by the well known British street artist known as Banksy.
It was really hilarious + plus very educational! (A winning combo!)Even the trailer for the movie is a riot. See above.
A lot of critics have speculated that the film isn't in fact a real documentary but rather an elaborate hoax orchestrated by Banksy. Either way it's still well worth seeing and will leave you wanting to see lots more of Banksy's fantastic + provocative work.
ps. I think the film has one of the best titles of anything EVER.