The Firefox add-on Ghostery watches any web sites that you are watching and could block any hidden scripts (if enabled) they are using for tracking you.
Ghostery alerts about the web bugs, ad networks and widgets (e.g.: Sitemeter, Facebook Beacon, Amazon Associates, etc…..) on every page on the web.
You can also block (on /off) any hidden script from the Ghostery option menu (In Firefox, Tools – Ghostery – Manage Ghostery option). So you can surf the site faster.
This add-on supports Firefox 3 – 3.5 and works with Windows, Mac and Linux operating systems. Install Ghostery from Mozilla add-on site.