Fake Tour

This prank only works if your friend has a show, band, etc. that they really love. Print out fake flyers and put them all around where they will see them. On the flyers, put a fake date, address, and time. The address that you put on the flyer should be an empty lot or field. Put a sign with a message reading "you got pranked" or something similar at the address. You will make them go through all that trouble for nothing.

If they don't see the flyers, try subtly mentioning the flyer location or lead them there.