Since Friends and those kind of hugely successful, expensive shows started bringing in huge stars for cameos do you think there are really any surprises left?

Who would you be shocked to see in a show/film?

Do you know of any cool cameos before it was common?

(What made me think of this was how I still, after many many years, can't believe that Nicholas Parsons ever agreed to appear in this
http://www.imdb.com/title/tt0095664/ - it's on 4OD if you've never seen it!)