Remember back in eighth grade, when you would communicate with your friends by passing notes? Digital SMS text messaging has replaced note passing in most places, but now you can relive that feeling with Moleskin's analog SMS system.
Instead of a phone, you use a specially equipped notebook that has a bunch of preprinted tear-out messages, and a built-in elastic band in the cover (used to hold it closed on other Moleskine notebooks) for launching your note. Maximum range is about 17 feet, so you can forget about telling your partner that you're stuck in traffic.
Okay, so it's pretty useless as a communications tool, but at only around $15, it's a cheap way to have a little fun.