The thin man: Simon Pegg is an honorary heavyweight in Run Fat Boy Run

As director, actor David Schwimmer doesn't supply the sixth-sense timing or jittery visual panache that Pegg gets from his usual collaborator, Edgar Wright, which stifles the sight gags. But Schwimmer gives the movie a warm, slightly scuffed look that suits its spirit. And Pegg remains one of the only comic actors working today who's as adept at banana-peel pratfalls as he is at delivering brainy verbal wit. In the best visual gag, Dennis, suffering from a runner's rash in his "scrotal zone," takes advantage of a mannequin's outstretched hand for a scratch, unaware of the crowd gathering in the lingerie-shop window. He maneuvers his convex body in contortions of shameless delight, showing a top-that gusto that the old comics would have applauded. Make that man an honorary fat guy.