[Keep in mind this is my first instructable]
Want to hide your Data From almost every one?
Just follow this and I'll show you how I hide my "Secret Files"

What you will need
Usb memory stick (for both Projects): £5-£25
GameBoy or Gameboy Advance Cartridge: Free-£9
Triwing Screw Bit (for gba): £2-£4
Nes Gamebit (for GameBoy): £2-£4
exacto Knife or razor blade (For GBA mod I'll Explain later): £1-£15
Secret Data Storage: Priceless
Estimated Total: £10 (on the low end products)

Step 1: Taking Them Apart

For Both Carts you will need security screws

Step 2: Assembly

The fist way is to put the memory stick in with the Gameboy PCB but it is a tight fit but the least suspicious.

The second way is to just put the memory stick in by itself but it will resemble a broken gameboy cart that will ether end up being thrown out by someone who dosent know or being opened to be fixed by a person who has some tec skills in a bid to fix the game (Trust me you don't want ether of those to happen)

Then on the GBA mod the memory wont fit normally so you will need an exacto blade or a razor blade to cut away the axes plastic but even at that the PCB will not fit into the cart case (so it is better and easier to store a micro-SD card in there.)