Coding a css 'Mega Drop Down'

Often used on e-commerce or large scale websites, mega menus are becoming more and more popular, as they offer an effective solution to displaying a lot of content while keeping a clean layout. In this tutorial, we’ll learn how to build a cross-browser, awesome CSS-only drop-down mega menu, using nice CSS3 features.

Src: http://net.tutsplus.com/tutorials/html-css-techniques/how-to-build-a-kick-butt-css3-mega-drop-down-menu/