I go to Ambercon NW every year, and one of the fun things about that con is that we all know all of those characters in and out, and there are a lot of games listed as "pick an Amber character and put them into X reality" where X could be just about anything.
John Kim ran 1,001 Nights one night and we played very young Amberites trapped in the castle with a very fickle and cruel Obberon telling stories to pass the time. It was great because we already had all our cues for the roleplaying. It was also a very in-character game, which is something I've taken to all subsequent games of 1,001 Nights and it really flies.
This year I'm running a mashup of Amber and Akira, and a version where the Amberites are staff at a TGIFridays type eatery called Nine Pieces of Flair.
Does anyone else do this with other fictions? Have you done this? Would you be willing to give it a try with say Star Wars characters in the old west for example?
Feel free to expand upon the topic to your heart's content.