The IMDB reports:

Actor Ewan McGregor has a warning for fans hoping to meet him at the stage door of his new London play - don't bring any Star Wars memorabilia. The Scots heart-throb is starring in the West End production of 1950s musical Guys And Dolls from June, which opens only 12 days after Star Wars: Episode III - Revenge Of The Sith hits cinemas worldwide. And while McGregor is prepared for the Star Wars frenzy over the next few weeks, he is banning the sci-fi film from the back door of the Piccadilly Theatre. McGregor explains, "I made a decision a while back, I'm not going to be available to sign Star Wars stuff at the stage door. I'll be available to sign people's programs and things. But if I start that it will be a nightmare. What will happen, people come to Guys and Dolls and want their program signed, but get monstered by the professional autograph hunters. I don't like to play that game so I won't be signing any Star Wars stuff."

Thanks to Fuuufuu for the alert.