I believe I read that after the movie the book was reprinted from that time forward as Bladerunner. I think if I read that correctly that that is the only book I have ever heard of changing it's title.
I didn't really care for the movie. I understand why people like it, it was interesting turning it into a noire type feel, but it just deviates from the book and the questions raised in the book about what makes us human that I just couldn't get into it.

Oh, there is a movie version of A Scanner Darkly, but I didn't mention it or review it because I wanted to start getting some reviews on the board and contributing more. I'll probably put the review here instead of the TV & Movies board though today at some point. It is a bit of an odd watch because it is done in rotoscope, but the movie stays pretty true to the book. Keanu Reeves is Arctor, Robert Downy Jr. is Barris, Woody Harrelson is Luckman and Winona Ryder is Donna. Excellent casting.