Well....[EDITED]

Well, the first thing I can think of: you can give it to me ;)

Meat Water

Creat a puzzle or give this key to random commenter.

on second thought, you could create a hard puzzle on itstoohard.com, and put the code in the end, and the first smart person could ninja it down. I think that's fair.

You can trade it with me to Magicka Bundle or Metro 2033 key. ;)

As it is probably region-locked (can be activated in Poland only) , you could probably make a group giveaway for users from Poland.

Write it on a piece of paper, put it on top of the Eiffel-Tower or any other tall building and the first person athletic and daring enough to climb up gets the game ;)

Well most of us don't really know how itstoohard work... So please just not that :D Give us equal chance to win it :)

Well, i will do 2 things:
Firstly is to participate in Total Biscuit Blood Bowl tournament!!

After that i will sacrifice all captured enemies in the name of Lord Cthulhu!

WhahahahahhHAHAHAHAHA!!!

You can tape a video of you singing the key and then send it to a user on SG with a HUGE number of entries, registered 1 year ago or so, but 0 wins. You'd be batman+santa. You'd be santabatman for that guy!

A tournament,maybe something like the Minecraft version of the Hunger Games,or maybe a TF2 match with the person with the highest score wins :)

Oooooorrrr you could...you know...do something like...making a giveaway.

You can use the key to unlock the secret door.

EVEN BETTER! Send the user I mentioned above a postcard with the serial key written on it :D Was this done before? I think I saw something similar around here, not sure...