Do you have a favorite paranormal story and/or urban legend? When did you first hear it? What's the story behind the story?
I've always been quite fond of The Vanishing Hotel Room - mother and daughter check into a hotel, daughter has to go out to fetch some medicine for her mother, and when she gets back there's no sign of her mother, all the hotel staff deny all recollection of her mother having been there, and the hotel room's changed beyond all recognition.
I still reckon it'd make a wonderful basis for a pleasantly creepy episode of Doctor Who. Mr. Moffat, if you're reading this..?