Here are some of RG's favorite fast and easy revenge ideas (great for April Fools):
– Clear plastic wrap on the toilet seat (works great first thing in the morning)
– Transparent tape on the bottom of the computer mouse (works equally well with ball and optical mice)
– Faked credit card bills, quite easily done with current scanner and printer technology
– Buy some really nasty magazines and some address labels for your printer. Put your victim's address on the labels and add a line that says "Subscriber since 2006", stick the labels to the magazines and drop them off in their mailbox.
– Get a friend to call your victim about an upcoming tax audit
– Blind date setup that ends up being a no-show date
– Salt in the sugar bowl