You make a good point, how would one go about doing that?
Ofcourse the gays will lie and say they never had sex in a year probably after they screwed 5 guys the night before.
I have heard horror stories of folks getting diseases in the US including AIDS through blood transfusions. I for one would like to have my own blood on hand and not chance getting AIDS, Hepatitis or any other disease for that matter.
Not sure. There is at least one post above saying you cannot do that. However, I believe if you are facing a surgery that is non urgent, you can work with the hospital to donate your own blood into their blood bank and it will be held for your operation. I guess the trick is to bank enough to cover any contingency and afterward release any leftovers into the system.
Best bet, ask your doctor.