I've had a big pile of quarters on my desk at work for a long time, and what better place to stash them than in this nice little treasure box? The slot on top is sized for a standard quarter. If you're willing to commit to saving up for a rainy day, print it as a single object, and when it's full you can smash it open. If you'd prefer to keep it re-openable, there are holes in the back and front that are designed to be threaded with zip ties for a semi-permanent seal.The OpenSCAD file attached is parametric - you can adjust the dimensions and the wall thickness by using the parameters on top.There's a lot of room to add more surface detail to this model if someone wants to jump in with some derivatives. Also, I'd love to design a version that has snap-together hinges, or better yet, the dovetail-groove style connection like in http://www.thingiverse.com/thing:11977 for a nice, snug closure.The parameters in the file fit comfortably on the bed of my ToM Mk7 with room to spare. You can probably print it almost to the full size of the build platform.I printed my copy at 30% infill, .32 layer height, and 35 feed rate, and no support. It came out pretty well with only a few hanging threads on the underside of the top of the arc of the lid. If you print it in two parts, thread the zip ties such that the ratcheting part is on the outside of the box, but don't tighten them all the way until you've threaded them all. Once you have cinch them down tight for a good seal.