Since I'm pointing out audio interviews at the moment, here is one with Ray Kurzweil:
In the near future blood cell sized robots called nanobots will travel our bloodstreams making repairs. He sees this as one part of a larger trend of achieving immortality through technology.
Kurzweil has another new book that covers the topic - The Singularity is Near, When Humans Transcend Biology - coming out soon. This is more of a focus on the path to what he described as "Bridge Three" in Fantastic Voyage: the logical end results of applied nanotechnology and bioengineering put to work extending the healthy human life span. It'll be a good few decades before we see any of this reduced to practice, however, which is why it is important to take good care of your health now - it'd be a shame to miss the boat on actuarial escape velocity and radical life extension just because you let things go to seed.