This small safe is good for hiding notes and other tiny items.

Supplies

Power cord (with at least one end USB)
Reusable tape (I used glow-in-the-dark)
Superglue
Scissors
Screwdriver (possibly)

Step 1: Dissect the Plug

Cut off the USB end of the power cord. Then pull the metal plug out. (circled in blue) (This may take the inside of the plug with it, in which case you cut the plastic part off the metal plug. If only the metal part comes off, you will have to either push the plastic part out with a screwdriver, or dig it out with a knife.)

Step 2: Glue

Hold the end of the metal piece slightly inside the outer piece (circled in red) and glue by dripping a couple of drops of glue in the end opposite the metal end. Let dry.

Step 3: End

Trace the nonmetal end of the USB drive onto a small piece of reusable tape and cut it out. Then stick it onto the end. To put stuff in it, just peel back the tape, put stuff in it, then stick it back down.