1) Make a list of 15 characters.
2) Assign each character a number.
3) Without telling anyone who's on the list or the character's assigned number, get questions from your flist about what they'd like to know about them. IE: "If 3 and 4 were trapped in a cave together with only a blanket and a toothpick, what would they do?" (The more random the better!)
4) Post the answers and who was who on the list.