A customer of the Web-based service 23andMe sends in a sample of spit and, for about the cost of a Sony PlayStation 3, receives a genome-wide analysis of nearly 600,000 genetic variations. The results include an estimate of genetic risk for various diseases, along with other personal information, such as where the customer's ancient ancestors might have come from.

The service's $399 price tag and its analysis of some quirky genetic traits, such as type of earwax, ­epitomize Linda Avey and Anne Wojcicki's ­populist approach to the genome. Avey, whose expertise is in business development for the biotechnology industry, and Wojcicki, who has a background in health-care investing, have also given the service a twist by harnessing the popularity of social networking; clients can compare their genomes with those of friends and family. TR senior editor Emily Singer recently visited Avey and Wojcicki at their offices in Mountain View, CA, to find out what it's like to delve into one's own genome.