I have been studying why we age. It turns out that basically we are programmed to live and there is no genetic basis for aging, but it is damage to our cells that causes aging. I believe that in the future, nano-technology will create extremely small robots that will be programmed to go into the body and repair cellls en-masse, extending life. From another direction, people like http://en.wikipedia.org/wiki/Aubrey_de_Grey are identifying at the genetic and molecular level what actually happens and how we can extend life, to the point where we could live to be 1000 years old, and for much of that time we would be young. The question is, would you want to live this long?