How about making adverts for films that will never get made?
Harry Potter And The Herpes At Uni
Darth Vader does a NHS infomercial
John Smeaton in The Smeatonater
Jesus on an unaired Club Reps episode
Bi-Curious George
Plenty o potential. When it's an ad it can be shit short and suggest a feature film of it exists. In fact the worse the film idea the better. Fool-proof!