Codecanyon - jQuery Splitscreen Plugin (Full Rip)
Splitscreen is a unique, interactive, fullscreen billboard-style jQuery overlay plugin with three modes: splash, promo, and teaser; and several options for plugin customization.
Simply add the Splitscreen Css and javascript files to the head of your webpage and initialize the plugin at the bottom of your webpage, leave the rest of your webpage content in tact and Splitscreen will appear.
Demo/Info
http://codecanyon.net/item/jquery-splitscreen-plugin/407649