Has this ever happened to you?  Just as you're about to snap a picture, someone jumps in the shot or holds up rabbit ears behind your head?  Cameron Diaz and The Tonight Show's Jimmy Fallon has a blast photobombing tourists who had no idea what was being done behind them as they smiled for the camera.

Nice touch with the Pharrell Wiliams hats.  The reaction of the final group of tourists is the best.  They're amused and so am I!