You should check out this awesome interactive tool from Google.org (Google’s philanthropic arm) called Google Flu Trends. Apparently data mining of search terms and search data allows Google to accurately predict the rate of flu infection throughout the U.S.
Google.org Flue Trends Map. Click to resize.
Since the 28th (date of the image above), the map has changed to indicate a higher threat for flu in the western and southwestern states. Overall, the threat level is only slightly elevated. Be sure to check out the FAQ for the cool videos and explanations.
//EDIT: Check this out – Google has plotted all of the swine flu outbreaks using Google Maps.