Concealing USB flash drives, money, and other small things just got easier, thanks to the clever “Doorstop Stash”. In a nutshell, you’ll need a “suitable hollow-core interior door, a cigar tube, a few tools, and some other odds ‘n’ ends.” Best of all, if your door is large enough, the stash tubes can be modified for larger items (paper documents, etc.). Instruction page. Click here for more pictures.
Not many people think of the space inside the door as a hiding spot, but it’s right there in easy reaching distance when you need to get to it.