If you have not tried Internet Explorer 8 Final yet I strongly urge you to do so, the new feature packed browser is considerably faster then earlier versions rendering pages perfectly, while every IE8 user knows about new features like InPrivate browsing, webslices etc. very few know about InPrivate Filters a smart content blocking functionality which can be used to block advertisements in Internet Explorer 8, Once activated from statusbar or shortcut key - CTRL+SHIFT+F smart InPrivate Filter automatically learns, detects and blocks common repeated-content from ad-servers appearing on websites you visit.
The best thing about InPrivate Filter is that you can easily manage the block list and even import filtering patterns similar to ad-blocker.