One of the things that should be the most precious to us is time. Even billionaire investor, Warren Buffett, knows this: "It's the only thing you can't buy. I mean, I can buy anything I want basically but I can't buy time." As everyone knows, we only get a certain number of years on this Earth. 78 is the average, or 90 if we get lucky. No matter what, time is the only non-renewable resource that exists. Or is it . . . ? Some people believe that medical and technological advances will eventually lead us to a point where people can live drastically longer lives. 100 years might become…