Dozens of genetic testing companies have cropped up over the last decade, promising to help consumers decipher everything from their risks of certain illnesses, their family trees, their wine preferences, and the diet most likely to help them shed a beer belly. As genetic testing becomes cheaper and more ubiquitous, what are the limitations and potential pitfalls to be aware of? How might insurers or employers use this information? Could we be on the cusp of mass genetic discrimination?