Fake blood, for use in real humans, is on it's its way. On Monday, three medical organizations in the United Kingdom announced a joint research project to create "synthetic blood."They'll make the blood by growing stem cells from embryos destined to have type O-negative blood into mature red blood cells. Their goal is to start testing the synthetic blood within three years and have practical treatments available in "five to 10 years."If they pull it off, there could be, in principle, a limitless supply of disease-free O-negative blood on hand for emergency transfusions at the scene of an accident or on the battlefield. It's ethically thorny (the stem cell thing, again), but it's certain it'd save lives.And, to look a little further ahead, once we have synthetic blood what's to stop us from enhancing it to deliver oxygen more efficiently, or keep you from getting drunk (or keep you perpetually drunk), or whatever? The singularity is nearer.