My Anti Spyware

The Adblock project

Adblock is a content filtering plug-in for the Mozilla and Firebird browsers. It is both more robust and more precise than the built-in image blocker.
Adblock allows the user to specify filters, which remove unwanted content based on the source-address. If this sounds complicated, don’t worry: it’s not.
Just add a few filters. Every time a webpage loads, Adblock will intercept and disable the elements matching your filters. See?- nothing to it.
Great! …but how do I add filters?
After you install / restart, an Adblock-item will be present in the tools-menu. This will launch Adblock’s prefs.
A selected filter can be edited by double-clicking or pressing ‘enter’. To remove it, press ‘delete’. New filters can also be added here or directly in the web-page: just right-click an ad and choose the Adblock option. For plugins, an Adblock-tab will appear atop or below the media: just click the “Adblock” text.
[Note: if you encounter a plugin, but don't see the Adblock-tab, don't worry -- the plugin is just cropped. Adblock has this covered. Choose "Overlay Flash" from the tools-menu, or type its shortcut. Now, you can directly click the overlay.]
Adblock supports two types of filters: simple, and Regular Expression.
A simple-filter is just a string of text with one or more wildcards (*). Regular expressions are much more complex, allowing precise control over filtering. In Adblock, as in all javascript, regular expressions must begin and end with the forward-slash: ‘/’.

More info about AdBlock here.