Stephen Sullivan，Stephen L Sullivan, or "Sully", is an actor based in Los Angeles, CA. He recently can be seen portraying "John Lennon" in HBO's exciting new series, "Vinyl", in episode 8, "E.A.B.". He is well known for his role as "Clay" in AMC's "Mad Men" for his encounter with Roger Sterling at the hippie commune in the episode entitled, "The Monolith".