Photos: Hamm, Carell visit 'Sesame Street'

OK, so your 4-year-old probably doesn't know Jon Hamm from a hole in the ground.

Still, it's cool that Sesame Street incorporates celebrity guests, which add spark for adult viewers roped into watching Elmo for three hours.

Sesame Street kicks off its 43rd season next month on PBS Kids, and it sounds like it'll be a pretty star-studded one. Look for guest appearances by Hamm, Halle Berry, Melissa...