That's kind of creepy. Do you want to know what it's used for? Say there was a car accident where someone was horribly injured and needed 5 pints of blood STAT! Do you want to know that 2 of the pints were yours? And the name of the person you saved? So they can send you a thank letter? And what if they didn't send you flowers or something, would you demand your blood back?

These are tough questions, are you prepared to give and receive? I think the better option over giving blood would be to give a kidney or liver, something that you know who is getting it. When Susan Butcher a few years ago had cancer and she needed a donor I went in to get my marrow tested. That would have been cool to say I saved her life, but someone else got that honor. Maybe that's how they should go about it, as most people are like that, they just want a little recognition. So you sign a piece of paper at the hospital allow them to use your name to get you organs or blood and maybe do a meet and greet with potential donors. I'd probably sign that.