Tracking the flu

Here's a fascinating article about how Google is able to accurately determine the number of flu cases at a given time based on search requests for things like "flu-like symptoms" that are fed into its search engine. People are using the web in truly ingenious ways! (There was a report a few months ago that a scientist was able to show, using Google Earth images that could show the direction that cows faced (but not where the front end of the cow was), that cows tend to line up along a north-south direction, which may indicate that cows, like many animals, have a direction-sensing magnetic organ.)