Hmm... I think the real question here is, what pranks haven't I done?
You name it, me and my friends have probably done it.
Prank calls are the greatest. Last summer, me and my buddies were all messed up on some drugs, and we were making prank calls, and we put them on speaker phone and we tape-recorded it. That was hillarious. Then like, a couple weeks after that, we found the tape in the recorder, and we didn't know what it was (because we forgot what we did that night, damn drugs). Then we listened to it, and it was hillarious.
Hmm..... What else... I did something like bobcat. I called up this guy, and asked if he was a member at WonderLand (an amusement park). He said "yes", and so we told them that he was randomly picked in a contest, and he won a free 25 year membership to Wonderland for him and 3 other people. The guy got so excited, and then we told him that the forms would be sent in the mail. Lol