I was thinking. So, the Blood Bank. They come to my workplace with the blood bus probably every other month. I usually sign up to have my blood drawn because a) it's sort of fun, b) free cookies and juice, and c) nothing is new on Reddit. I did it initially because neither I nor my parents could remember my blood type (O+). The first time was a bunch of scary forms and people asking me if I'd had sex with any men recently. Now I have a card, and the whole process takes about 15 minutes (they still ask about the men, though).

My thought is: they have to test the blood, and for liability purposes, they have to be able to source the blood back to its donor (in the event that the donor lied about any communicable diseases, etc.). This means complex systems in place associating bags of blood and a database of users. I don't care so much that they have my information, it's necessary, and I volunteered it. What would be cool, however, is if they had a system in place to, say, email you whenever your blood was used.

I'm fairly sure there's an "expiration date" on donated blood, and in all likelihood, my blood expires before it ever gets used in a hospital (there's nothing special about my blood type). It would be fun, though, to know if it was used, if for nothing else than to solidify the association in people's minds that donating blood has an effect, and every time you donate, you might get a short email saying that your blood was used.