Borrowed from my friend Bobbie's Facebook page:
Become a Bone Marrow donor, all from the comfort of your home...and it's FREE! Enter the promo-code PIF070109, save your 52 dollars, and possibly save someone's life. Neat-o! https://donors.marrow.org/
I used to work at Fred Hutchinson Cancer Research Center, where bone marrow transplants where first pioneered and always meant to get typed for the bone marrow registry. When you sign up online they send you a kit with cheek swabs, so you don't even need to give blood to be typed. It's especially vital to do if you're not Caucasian since it is often very difficult to find a matching donor for minority or multi-racial patients.
I'm all signed up. Now it's your turn. :)