Monitoring with a focus on browser experience. Plans are €10/month for simple, $50/month for 1 browser, $100/month upwards for the full service.
Web browser testing and automation framework / suite. Similar to selenium. Cross platform, cross browser. Hat tip sfllaw.
Very handy CSS hack cheat sheet. Includes a whole load of IE5 / IE6 / IE7 stuff. Came in very useful for an all but IE7 selector. :)
How to install Internet Explorer 6 and 7 side by side. *Very* useful for development and testing.
Install Internet Explorer 5, 5.5 and 6 in one easy script