Nintendo is giving away free WiiMote Keychains if you register your copy of Big Brain Academy: Wii Degree on their website and fill out a quick survey. The survey is supposed to tell Nintendo how you like the game and where you bought it and etc. The offer is only good for the US and Canada areas only. And there is only one per household, sorry.
To make sure you don’t go insane trying to make the keychain work with the Wii, Nintendo added this last line to their website: “Wii Remote keychain is not operable and will not work with your Wii console.“.
So if you have the game, you can sign up (or login), register your game, and fill out the survey here.