The new Mozilla prism is a beginning of a new era on the web, you don’t have to use a browser any more, the desktop and web are closer then ever.
Change any web page into an application.
You can have an icon of your favorite site on your desktop thus eliminating the need to open your browser. I know it sounds a bit useless, but believe me it's another step towards a virtual desktop.
You can download it as an add-on to your Firefox browser or as a part of your operating system.