If you start wasting somebody's time at NASA, this is how they're going to get you out of their office. Or it's how JPL engineer Mark Rober will anyway. This hacked Nintendo console will definitely put you on notice.
It's really fairly straightforward. You take an old Nintendo console (a broken one, hopefully), gut it, and add some custom components such as an Arduino board, a speaker, battery, LCD-display and a motion-detector. It will take a little cutting and soldering, but it's a pretty sweet-looking box when all is said and done (of course, you could put the guts in anything you want, really).
They've even included a zip file you can download, which contains not only all the code and libraries to make this work (so you don't really need to know how to program), but there is also a parts list with hyperlinks to exactly where to buy the parts. So all you just need to figure out what sound file you want to put on the SD card. When someone passes by, the sound file begins to play and the timer starts ticking down. When they pass by again, the mechanism stops. Simple, but cool.
Personally, I think the 400 seconds they have it set for is waaay too much time, but that'd be easy enough to fix in the Arduino code. Just swap out 400 for a lower number. The real question is what would you do with it? You've got a box with a motion-detector that will play any sound file (song, ambient noise, sound effect, recorded speech) when someone walks by, and then stop when they walk by again. Haunted houses, sure, but there have got to be some amazing pranks you could pull with such a thing.
Get creative and have your best ideas on my desk within the hour, Johnson. My "desk" being the comments section below. [Mark Rober]