All right, for the majority of people out there, the DIY Reverse Geocaching Briefcase will probably elicit a huge question mark and “Huh?” moment. Well, let us shed some light on what this puppy is able to do. For instance, you can program it with specific co-ordinates, making sure it can open up only on the exact spot – thus leading to some interesting scenarios such as making the recipient of the gift working really, really hard for it. Of course, this DIY project requires an Arduino, GPS sensor and a bunch of tubes to make it happen. When programmed, it will make use of the GPS sensor to display the distance to the location on the tubes. The moment you’ve reached the right spot, a motor will then release the latch that once held its possessions inside dearly.