David Prowse — British Actor born on July 01, 1935,

David Prowse, MBE is an English bodybuilder,weightlifter and actor. He played Darth Vader in the original Star Wars trilogy, though the character's voice was provided by James Earl Jones. He also played the Green Cross Code man, a character used in British road safety advertising... (wikipedia)

I've seen the teaser trailer for Revenge of the Sith though and I think it will be excellent.
Actually, the Department of Transport were at one stage going to sack me.
George Lucas was casting about and had heard favourable things about my work in Clockwork Orange and asked me to come in, which of course I did even though no one knew what the film was about!
My agent set up a meeting with George Lucas. They were casting in England.
I do remember smiling quite a bit inside it though since I knew it wouldn't be seen on film - so of course while the poor planet is being blown up I'm smiling and laughing like mad!