Web search engines have become pervasive in recent years, obtaining information easily on a variety of topics, from customer services and goods to practical information. Beyond these search interests, however, there is growing interest in obtaining health advice or information online. As a result, health and health policy researchers are starting to take note of potential data sources for surveillance and research, such as Google Trends TM , a publicly available repository of information on real-time user search patterns. While research using Google Trends TM is growing, use of the dataset still remains limited. This paper offers an overview of the use of such data in a variety of contexts, while providing information on its strengths, limitations, and recommendations for further improvement.