Honestly, just read the first post, but it got me thinking.
No, it is impossible. Humans die when their cells begin to malfunction and fail in large amounts.

This having been said, you should also know that this generation is the first that will die younger than the one before it. It is a result of our lack of proper nutrition thats speeding up our species' physical degeneration (Check out this book, for cool stuff about that: Nutrition and Physical Degeneration by Weston Price )
Now, at this rate, our life-spans will only get shorter and shorter until we wisen-up as a whole.
(Physical degeneration is also why cancer is so popular now-a-days, by the way)

Now, why is immortality impossible? It simply is. Nothing lasts forever, and even if they could vastly prolong your natural lifespan, cancer would eventually incapacitate you, or you would rot from the inside out. In short, we can't live forever because too many factors affect our bodies to counteract them all.


I hope this made some sense. If not, ask for me to clarify and I shall.
-Andy