Google Flu Trends is based on the simple idea that people who are feeling sick will probably turn to the Web for information, typing things like “flu symptoms” or “muscle aches” into Google. The service tracks such queries and charts their ebb and flow, broken down by regions and states.
This could easily be gamed. A better way is to track the actual outbreaks in real time, by texting. Exactly what Dr. Brilliant spoke about in his NY Times magazine article a few weeks ago.