Google has also set up an HTML5/CSS3/JavaScript showcase, “Chrome Experiments”:
http://www.chromeexperiments.com/
These experiments were created by designers and programmers from around the world using the latest open standards, including HTML5, Canvas, SVG, and more. Their work is making the web faster, more fun, and more open – the same spirit in which we built Google Chrome.
Google is also accepting submissions based on JavaScript.
One recent “Chrome Experiment” has been attracting attention: an interactive music video for Arcade Fire’s “We used to wait”: http://www.chromeexperiments.com/arcadefire/