Is Guest-Star-Happy 30 Rock Mad for Jon Hamm?

It's getting to a point where "Frank," "Pete," "Twofer" and "Cerie" probably wonder why they come to work anymore.

NBC's 30 Rock refuses to ease up on the guest-casting gas pedal, this time setting its sights on Man of the Month Jon Hamm. The Mad Men star, says EW's Ausiello, is being eyed for a multiple-episode arc on the extremely funny yet underrated NBC comedy, likely playing a neighbor of Liz's. (Hmm, he must live on the other side of Fred Armisen's "terrorist.")

Asked to confirm Hamm's rumored visit, a 30 Rock spokesperson said, "Unfortunately, we can't."

Hamm, who is oh-so-serious on Mad Men, tried out his comedic chops as guest host of the Oct. 25 Saturday Night Live.

Other Big Names heading for the Rock this season include Oprah, Steve Martin, Salma Hayek and Jennifer Aniston.