Being typecast is one of the fears of modern actors. Take Mark Hamill, for example. Everyone knows him as Luke Skywalker, and he hasn't had a decent role since Star Wars. Some folks are able to break out of being typecast, like Drew Barrymore and Alyssa Milano, two squeaky-clean kids who had to work at changing their image. Some folks make a living on their being typecast, like William Shatner and the rest of the Star Trek folks. Talking at conventions and signing autographs keep them in the spotlight and in the minds of their fans. Even when more work comes along, it is usually in the same field, such as Star Trek's Chekov having a recurring role on Babylon 5 as Bester.