Dean Edwards has taken it upon himself to make Internet Explorer W3C compliant. How? Well, it isn't by patching the app, as you might suspect. He's created a stylesheet, dubbed "IE7" that uses DHTML to load and parse style sheets into a form that IE can understand. Just include the stylesheet in your HTML pages, and things should render correctly.
The complexity of the CSS transformations is really amazing and shows off the power of this stuff. Of course, the real question is, how long until MS sues over the use of the "IE7" name?