EDIT: All orders are now being cancelled. If they manage to ship you one, you are very lucky.
1) Go to: www.smartmusic.com/freetrial
2) Use code: SM123educator
3) Fill out the sign up form
4) last option (USB Vocal Headphone/Mic) is the best choice (for gamers)
EDIT: As per comments in this thread, Free shipping or not depends on where you live apparently (most likely USA only). Make sure you select Ground Shipping, not Express Shipping.
NON-USA RESIDENTS: Try the other options, apparently the other headsets/mics aside from the last one are available for free shipping outside the USA.
(found via Reddit)