Pseudo Elements for Fun and Profit
From minnestar Wiki
We'll be talking about a very small part of the the vast canyon of CSS: pseudo elements. Essentially, for every element on page, you get two free elements you can create through CSS via the :before and :after "selectors." They are part of CSS2, so the browser support is pretty deep, but the things you can do with them are rather amazing. And since this all happens in the CSS, markup remains clean and uncluttered.