Joseph Gordon-Levitt Weilds a Mallet in Delightful 'Sesame Street' Appearance (Video)

The actor-writer-director made an appearance on the PBS kids' show, bringing a new vocabulary word and some bubble wrap along with him.
Murray, left, and Joseph Gordon-Levitt

The word of the day is: "Versatile."

Sure, Joseph Gordon-Levitt actually was teaching kids the definition of "reinforce," but the real story here is how the 31-year-old can jump from writing, directing and starring in a film about a guido with a porn addiction to smiling and playing along with a red puppet named Murray on America's most-loved children's show.

Gordon-Levitt's film, Don Jon's Addiction, made a splash at Sundance; the wristwatch that Murray tried to destroy in the vocab segment, however, stayed in one piece -- thanks to some last-minute intervention and handy packing materials that the star brought along.