anti-banner.css

What is it?

A stylesheet which makes use of commonly found attributes associated with banners. It currently uses element dimensions and DOM location, href fragments, link targets, borders, and common alt attributes to try to remove banner adverts.

Disable flash and popups, and you're well on your way to eliminating most of the superfluous distracting crap that litters many websites.

Where do I get it?

http://www.aagh.net/projects/antibanner

How do I use it?

First, you need a browser that supports at least CSS 2 selectors; this basically means Opera and Gecko based clients. Internet Explorer users need not apply.

Now you need to find how to specify a user stylesheet in your browser of choice.

Opera 5+

File → Preferences → Page Style. Hit choose under My Style Sheet, select your stylesheet, and make sure "My Style Sheet" is selected for Author mode.

Opera 7

Either follow the instructions for Opera 5+, or go into your Opera 7 directory, under styles/user/, and replace Hidecertainsizes.css with anti-banner.css — provided you've got "My Style Sheet" enabled for author mode, you can select "Hide certain sized elements" from the document style button and enable it independently of your current user stylesheet and all the other user CSS fragments it's bundled with.

Mozilla

Enter your profile directory (~/.mozilla/profiles/ under *ix, "%USERPROFILE%/Application Data/Mozilla/profiles/" under Windows), place your user stylesheet in chrome/userContent.css.

Internet Explorer

As I said, it won't work, unless you've maybe got hold of a beta of IE 7. If you want to try anyway, it's in Internet Options → Accessibility → User Style Sheet.