Last year I created a GreaseMonkey script called Invisible Web that notified you about the web beacons (web bugs) that the page you’re on is using to track your behavior.

Changes in this release:

• Favicons are now stored locally to increase performance.
• Updated definition for Lookery
• Updated definition for Google Analytics
• Added definition for Piwik Analytics
• Added definition for Mint
• Added definition for Facebook Beacon
• Added definition for TypePad Stats
• Added definition for Wordpress Stats

Install the Invisible Web Greasemonkey Script

Update: Invisible Web now has a Google Code Project