Jeffrey Zeldman Facebook Quotations

Wildly successful sites such as Flickr, Twitter and Facebook offer genuinely portable social experiences, on and off the desktop. You don't even have to go to Facebook or Twitter to experience Facebook and Twitter content or to share third-party web content with your Twitter and Facebook friends.

Even if it's not always the best markup, what are Facebook and Twitter? They're web standards with some scripts. They may not validate, but they're still CSS layouts and simple markup, and that's great!