How many actors have been cast at least twice for different parts in "Friends"?
I think that the nurse in the hospital where Carol gives birth is the same actress as "Estelle", Joey's agent.
The other one that comes to mind is "Guru Sarge", who treats Ross's "thing". I think he's also the director of the movie that was supposed to be Joeys big break, the one that was set near Las Vegas ("She's been dead for ten years..."... "Shutterspeed" or something like that.
Then there's the guy (Giovanni Ribisi) who accidentally dropped a condon in Phoebe's guitar basket when she was replaced by Chrissie Hynde's character - although that MAY actually have been Frank Buffay jr, but somehow I don't believe that this was intended that early in the show.
Any more? Bueller?