If you ever wanted to know about the Google AdSense ads that you have recently clicked from Firefox or IE, here’s a tip:
Open the history panel (Ctrl+H) in the browser and type googleadservices - you will see all the Google Ad URLs that you have clicked since the last time you cleared your browser history.
You can also know the exact web address of the Adwords advertiser from these URLs. Firefox 3 users can type googleadservices in the address bar and get the same information from the auto-complete entries in the drop down.
Nothing very useful but will give you an idea about how frequently you click on Google AdSense Ads on other websites.