[_n3o_] put together a nice external storage mod by fitting a 2.5″ drive into a broken Game Boy. This mod fooled quite a few people because it appears that the device still plays games with the drive stuffed inside of it. Sadly, this is not the case. The reflective backing has been removed from the screen and replaced by a piece of paper with a graphic printed on it. The LED from the hard drive was moved to the battery indicator for the Game Boy for added realism. There is no build log for this project but [_n3o_] did give a short explanation of it in a forum post. You can see two more pictures of the project after the break.
Update: Take a look inside too!