It can be a child's toy or a funny prank it is practical and still works if you want to put the cap on a bottle it makes it even better I hope you like this.
Step 1: What You Will Need
A bottle cap, inside if a flash drive, tape, super glue
Take the tape and the drive tape the port end of the flash drive shut so no glue can get in later.
Now put the glue inside the cap and lay the the flash drive with the tape side on the bottom.
That's it now you can walk around pretending you have a bottle cap but its really a flash drive to make it cooler you can put the cap back on the bottle.