Tom & Cameron Get Silly Off the Set

Tom Cruise and Cameron Diaz may be co-starring in the comedy filled action film, Knight and Day together, but the two have learned how to keep laughing even after the cameras stop rolling. Tom and Cameron were spotted smiling nonstop on the hotel rooftop in Salzburg, Austria Tuesday while promoting their new movie.

Maybe the root of all the laughter between the two friends was Tom's hilarious portrayal of Les Grossman and his ridiculous performance with Jennifer Lopez at the MTV Movie Awards.