Having known a 4-year-old who died last week because there was no match for her, I can assure you that the number of lives saved from organ/blood/tissue donation is staggering, but the number of lives lost because enough people won't commit to give, for one reason or the other, is even more so. An organ takes a signature and letting your family know, but donating blood is simple and painless and can be done often, and adding yourself to the national marrow donor registry even more so - it just takes a finger stick and filling out some paperwork. They are especially looking for non-Caucasians. You're more likely to have a match, even with blood, from someone of your same ethnicity. All easy ways to save multiple lives.
I would rather a rapist get my corneas and five other people get my other organs than for those five to die waiting. Giving of oneself must be completely selfless. For my little friend though, it's too late.