Who is Sick?

I ran across a reference to the Who is Sick service several months back. It lets you post symptoms and associate them with a particular geographic area. You can then see if other people in the same area share the same symptoms.

Part of me thinks it's silly, but I can also see how it could be valuable. Of course, not enough people in our geographic area post to it to make it worth while, but it's still kind of an interesting concept.