Not sure if it works for Linux, but I use Bumptop. It's not quit what you are thinking of but it does make your desktop 100x better. It renders it as a box so you can hang items on the wall or ceiling. It's really nice for organization, and quick access. It also has free form selection of items, and you can just start type in the game of what you want to select. So you could just type "Min" and hit enter, to boot up Minecraft.
