Blood Centers of the Pacific says there's a shortage on, so I went in to donate. Since I'm in good shape and my iron level is (they tell me) scarily high, they hooked me up to a machine which sucks my blood out, centrifuges it, takes red cells out, and then pumps the plasma and platelets back into me. They can get twice as many red cells out this way, though I have to go twice as long between donating.
Apparently I set some kind of speed record -- they'd never seen anybody fill the bag that fast and my time was, in the simple literal sense, off the charts. They were having trouble with their calculator so I got out my Palm and helped them calculate some level or other for my time being that quick. For those who care, it took me 22 minutes and I'm told a normal time is 25-30 minutes.
I found the whole thing quite amusing. Also, it's *really* weird to feel the needle pumping blood back *into* you. You can feel the vein vibrate even a significant distance away if you put your finger on your skin.