Gallium: The “Melt in Your Hand” Metal
No idea what you would actually do with this, other than have it and show it to people. Maybe this would be your thing if you were really in to The Secret World of Alex Mack girl.
It is pretty cool, though.
Apparently, gallium has a super low melting point, so just holding it in your hand heats it up enough to turn it from solid to liquid. Every order comes with three bullet-shaped containers of gallium.