Ever had the need to write upside down? How about under water? You never know when the mood will strike.So just in case, you really need this pen.

And even if you’ll never need a pen that works in space or sub-zero temperatures, the Metal Inkless Micropen  is impressive.

It’s inkless, because it writes in metal. It’s almost smudge-free, for pretty much the same reason.

Best of all, you’ll never need to refill the ink or sharpen it, giving it a major advantage over regular writing implements.

The lead-based tip will leave a permanent mark – so it’s probably best to keep it out of your mouth – and it comes with a keychain, so you can keep it close by. Get over to ThinkGeek.com to get one.

$38.99.