I've just always thought about this as something really worth while doing. An easy and free way of actually helping.
But, when I was telling my daughter about it, about how I will have about two cups of my blood drawn every three months or so, she said : "That makes me think of 'Twilight'... :-D
Well, jokes aside, I'm really glad I got around to doing this, and I challenge all my readers to do the same. You can maybe help save lives!