Google’s philanthropic side has published online a tracker that monitors how often people ask about the flu through Google.  They have found that it is a good indicator of flu in a particular area and is more immediate than CDC monitoring of flu.  Essentially, you can just monitor how often people in a particular area look up some information about the flu and this is a good idea of when it is breaking out in that particular area.

Take a look at the website - http://www.google.org/flutrends/