selectivizr is a JavaScript utility that emulates CSS3 pseudo-classes and attribute selectors in Internet Explorer 6-8
Selectivizr adds support for 19 CSS3 pseudo-classes, 2 pseudo-elements and every attribute selector to older versions of IE. It can also fix a few of the browsers native selector implementation.
Selectivizr works automatically so you don't need any JavaScript knowledge to use it — you won't even have to modify your style sheets. Just start writing CSS3 selectors and they will work in IE.