50 best inventions of 2008

Learning and sharing your genetic secrets are at the heart of 23andMe's controversial new service — a $399 saliva test that estimates your predisposition for more than 90 traits and conditions ranging from baldness to blindness. Although 23andMe isn't the only company selling DNA tests to the public, it does the best job of making them accessible and affordable. The 600,000 genetic markers that 23andMe identifies and interprets for each customer are "the digital manifestation of you," says Wojcicki (pronounced Wo-jis-key), 35, who majored in biology and was previously a health-care investor. "It's all this information beyond what you can see in the mirror."