If you're looking for a funny april fools prank, try this: Take your friend, and get their phone number. Then, make a post on craigslist, perhaps in the adult section, advertising someone really hot for really cheap. Think: The kind of deal that is too good to be true. Then spoof a couple of numbers and call them. Since you'll be the first to call them, you can make them all confused and whatnot. Then unleash the flood of people wanting cheap sexual favors on them. It's classy, for sure.