CrowdSourcing Your Blood. Muhahaha.

If you check out the Wikipedia entry on CrowdSourcing you'll see that the earliest recorded model of CrowdSourcing dates back to the 19th Century. The Oxford Dictionary was put together from slips of paper written by thousands of volunteers. (F.Y.I. - I learned tons about CrowdSourcing when I read the arguments on the discussion page behind this entry. Love those angry Wiki editors).

Despite the fact that the model has been around for a while, it's still being used in new ways to solve specific problems. I was rather interested to come across an article, (thanks to @dexin) about CrowdSourcing being used for epidemiology. It seems the Red Cross are using people's blood donations to screen for a disease called Babesia that can be transmitted by blood transfusions. By testing donations from a certain area, the Red Cross can decide whether or not the disease is widespread enough to merit the expensive screening of all blood donations for this disease. You can read more about this here. 

I suppose the practice of donating blood is in itself a CrowdSourcing activity. Can you think of any other existing activities that use CrowdSourcing in other sectors?