How's this for a container. A GPS enabled lock box that will only open when taken to the correct coordinates. Sound too good to be true? Well it exist.

GPS Puzzle Box Only Opens In One Specific Location

How cool would this be? To have a container that won't open unless its in the right place? Imagine the possiblities.

From the Article:

"The box has a button and an LCD display on the lid. When you press the button, the display will show you how far, in kilometers, you are from the goal location. It doesn't give you directions, so you need to triangulate where you're supposed to go via trial and error. Oh, and you can only press the button 50 times"

That would be a serious kick ass cache hunt. Too bad the cost would be prohibitive and the technology would make the cache very tempting for muggles to steal. Even worse, some muggle could find it and just press the button 50 times to render the cache useless.

Detailed blog post with pictures of the cache and its making can be found at here: http://arduiniana.org/projects/the-reverse-geo-cache-puzzle/