Of all the Saturday Night Live players in history, Jimmy Fallon is the one who is most likely to crack up mid-skit. That's just a scientific fact. Over the weekend, The Tonight Show host unexpectedly appeared with Tina Fey on their former stomping grounds, "Weekend Update," as undecided voters from suburban Pennsylvania. Fey commits, but Fallon may or may not have forgotten all his lines — plus, how to do his accent. It's funny, just don't expect it to make any sense.