I'm also not trying to disagree that people should donate...it's just that you really do have to have a surgical procedure if you're donating marrow. Moreover, PBSC involves a five-day injection drug regimen (filgrastim) that you need to undergo before you get to sit in the chair (http://marrow.org/Registry_Members/Donation/Donation_FAQs.as...). Either way, it's a far more involved procedure than (say) donating plasma -- which is how your post made it sound.
The FAQ also says that PBSC donation is considered "investigational" (http://marrow.org/Registry_Members/Donation/Donation_FAQs.as...), though who knows what that means. I just think people should be able to read the answers so that they know what they're doing.