I'd like to add my congrats as well.

Also, I don't think anyone has mentioned the health benefits of donating blood, especially for men and post-menopausal women. There are several different forms of iron in the blood, and one un-bonded form will build up in your plasma over time (especially if you eat lots of iron-rich foods) leading to heart muscle damage and other undesirable consequences. The best way to reduce the levels of this iron is to regularly donate blood. This is not the same bound iron that is found in the hemoglobin molecules, so not related to anemia. I'm not sure if the simple "iron drop" test at blood centers can discriminate between the different iron compounds/ions.

I'm working on my 6th gallon, and strongly encourage everyone to donate blood if they are able.