Google Health and Microsoft Health Vault both promise a new level of patient control over medical data, as well as significant privacy concerns. Both services enable users to share medical data more easily, as well as link to third-party applications such as reminder and tracking services. Google Health's interface allows users to create profiles and points them toward relevant information. Although patients already have the right to access their medical data, in reality that right is compromised by the difficulty of obtaining copies. Very few health-care offices either have, or are willing to transfer, electronic patient records. The few electronic portals that do exist are generally controlled by the health-care provider. With the third-party application aspect, patients could also be offered tools for using their medical data as well. Partnerships and pilot projects are underway for both platforms. Clearly, Health Vault and Google Health could mark a radical new step in the portability of medical data. Yet medical information is uniquely sensitive, and this concerns privacy experts. The Health Insurance Portability and Accountability Act doesn't yet cover this new type of service. More worrisome is the potential for third-party vendors to leak personal information and/or run into conflicts of interest. While these issues aren't insurmountable, the prudent individual will be cautious until some form of regulation is developed.