A video on YouTube
shows a MacBook Pro that has supposedly been hacked to rapidly change applications whenever it's smacked on the side. (Thanks to Kathy for sending the link.) I have to admit that when I first saw it, I thought it was fake. I figured the guy was probably pushing a button to make the applications change. However, after reading Erling Ellingsen's description on Medallia blog
of how the SmackBook was created, I'm now pretty sure it's real. He writes:
Turns out, the laptop has a built-in motion sensor. Nominally, it's there to protect the internal hard drive. The basic idea is this: If the accelerometer suddenly notices that the gravitational pull of earth is no longer present, the most likely explanation is that the laptop, sensor and all, is currently accelerating at 9.81 m/s² towards said earth. In that case, it will (wisely) try to turn the hard drive off in preparation for impact. It can, however, also be used in situations not involving lobbing the laptop across the room, fun though that may be.
More importantly, he also provides the code so that anyone else can hack the Mac's built-in motion sensor and create a SmackBook, if they desire. And a few people have reported successfully replicating
the SmackBook. It's a cool little trick, but I don't see it having that many practical applications.