Once, as a practical joke, my friend and I told this guy friend of ours that we knew a girl who had a crush on him. He was totally psyched about it and pumped us for more details so we made up a screen name for her and spent the better part of a month IM-ing him pretending to be her! Then he asked "her " for a picture of her so we cut one of a cute model out of an issue of TEEN, scanned it in and sent it to him. Needless to say he was lovestruck and has been trying to set up a date with his "dreamgirl" ever since.
We don't have the heart to tell him she doesn't exist!