http://phorsite.com/index.html#our_path Click on the button to the right of username and password and watch as the page changes. Is this css or a Javascript? Does anyone know what this is called? Background switch or something?
that sounds like Javascript to me since it has to deal with switching... javascript is the one that handles the fanciness of things like those. also, flash does this as well...
You could do this using JQuery or any of the other javascript libraries/frameworks. Does look good though, although I've not looked to see how the site looks when javascript is turned off. ** edit It works beautifully