Well, one day i was incredibly bored, so i thought I'd open the back of my phone and clean it, and while doing so, (don't ask me what made me think of it) I cut out a bit of paper and placed it behind the battery, so i can store passwords, or other things on there that i only know how to access.
Step 1: Materials needed.
To use this secret paper hider, or whatever you want to call it you will need:
1x Mobile phone (With recoverable backing and battery)
1x Sheet of paper
PS. Sorry for the flash on this photo, i had it turned on and i can't be bother re-taking it.