Validating the CSS on Twitter Bootstrap sites is always entertaining. Even (or especially) the official TB site.<p><a href="http://jigsaw.w3.org/css-validator/validator?uri=http%3A%2F%2Ftwitter.github.com%2Fbootstrap%2F&profile=css3&usermedium=all&warning=1&vextwarning=&lang=en" rel="nofollow">http://jigsaw.w3.org/css-validator/validator?uri=http%3A%2F%...</a>