Make anything you want out of sunlight and dirt

"Molecular manufacturing" -- using nanotechnology to assemble any desired product molecule by molecule -- "is coming soon — almost certainly within 20 years, and perhaps in less than a decade", according to this article. Its potential for improving human existence is immense. There are also significant risks, of course, but as the article points out, trying to prevent or delay the development of the technology would be the most dangerous thing we could do (since this would merely allow unsavory countries or groups to get ahead of us in the field, while preventing us from developing the technology base we would need to counter whatever malevolent use they might make of it). The Fight Aging site has a posting up on the implications for human longevity and health.

And, of course, for this and other reasons, everyone should read this book.