I liked the idea of a Super Mario style coin box, but wasn't entirely satisfied with http://www.thingiverse.com/thing:56102 and decided to make my own version. As it turned out, that was pretty easy thanks to the awesome Mario Question Box by BrianEnigma and the snap-top from Trezhunter's Nintendo 3DS Game Cartridge Case.
My changes were rather subtle, just added a solid wall behind the "pixels" in the box and removed the 3DS logo under the lid to make room for a simple slot capable of taking in any Euro coins and probably any other currency (except gold bars and cowry snails, for example).
- uploaded separate parts & a large (200 %) version of the lid so you don't end up scaling the coin slot too much!
Printed on an Ultimaker² with 0.2 mm layers and 20 % infill, should not need a brim and definitely no support ;-)