Also on these boards:
Bette Davis and Joan Crawford, in What Ever Happened to Baby Jane? The wig Bette Davis wears throughout the film had, unbeknownst to both leads, been worn by Joan Crawford in an earlier MGM movie. Because it had been re-groomed, Crawford didn’t recognize it. (via)
The Sixth Sense (1999). A fantastic movie, and the source of the infamous "I see dead people". If you have never seen it (unlikely), it is a must see. By the way, I love M. Night Shyamalan movies and this one is one of his best.