Currently, I have microSDs spread all around my house—I'm sure I could find a couple if I searched hard enough, but the bulk-majority are probably lost in the dusty corners for good. A USB stick that houses all your cards makes so much sense I'm surprised that this is just a concept. [Yanko]
How to easily hide "documents" in your house
1) Put the documents on a Micro SD card.
2) Unscrew the light switch plate of the room of your choice
3) Use the adhesive of your choice (I prefer duct tape) to secure it against the back of the plate.
4) Screw the plate back in.
5) Don't forget to get the SD card before you move to another place.