Just saw this article on boingboing.
For those that don't feel like following the link, it's about the National Geographic's Genographic project. Basically, send in a cheek swab, they'll analyse your DNA, and trace the broad outline if your ancestor's path from Africa through the whole history of the human race..
This is scary.
Greg Egan has long been a favorite author of mine - although his output has been decreasing, both in quality and quantity, of late.
You can read an excerpt from the story on the ebook site above..