Practice English Speaking&Listening with: Google Chrome alpha transparency screencast

For the moment at least you'll need Chrome Canary for this demo, and you'll

need to enable alpha transparency from the Chrome flags page. Now... this slightly

bizarre demo that we're going to show you has two WebM videos that use alpha

transparency. You can drag a video — note the use of blur and greyscale CSS

filters. You can drag one video on top of another, which changes the z-index,

double-click a video to fire a little CSS animation, and double-click the page

to swap out the background image with a video and vice versa.