Health surveillance & the internet

This article discusses detecting disease outbreaks through the internet. Wow.. whoever thought! Shoe leather epidemiology goes high tech. There are several sites that do this already, and they are growing in popularity and are quite intriguing. (Click here. Or here.) But it does indeed seem to hold up, at least to some extent - tracking disease through internet searches does seem to correlate with disease trends. The article uses a Canadian listeriosis outbreak as an example and has a nifty graph.
Screen shot of Google Flu (the Georgia trends, of course!)