The Locker Answering Machine
The Locker Answering Machine was a device made by Worlds of Wonder, which you'd stick on the inside of your locker door near the vent. I thought you were supposed to pound on the locker to start a recording, but someone in a forum says that the thing came with remote controls you'd give to your friends. There is almost no evidence that this product ever existed, despite being advertised on national TV. Only recently have just two references appeared on the Web, and those are just people asking about it in forums.