Click Fraud on Google

Google has laid out some more info about how they are tracking click fraud and ways to exlcude sites and even IP addresses for your Adwords Campaign.

http://adwords.blogspot.com/2007/07/whats-new-in-world-of-invalid-clicks.html

 Update: Google has dedicated this webpage http://www.google.com/adwords/adtrafficquality/index.html to the fighting fraud issue.