Google Chrome fans can create application shortcuts to achieve this. This release note talks specifically about Gmail, but it will work with any website.
Application shortcuts: You can create an application shortcut to access Gmail straight from your desktop. Simply go to Gmail while you're using Google Chrome, click the page menu and select 'create application shortcuts.' When you double-click a shortcut icon, it opens in a streamlined window.
It's also worth noting that Prism/WebRunner is not under active development, so Chrome app shortcuts will continue to get all the improvements that Chrome gets, and you con easily find a download link for chrome (currently, not so easy for Prism/WebRunner).
In Chrome > Click the Wrench Icon > Tools > Create Application Shortcuts...
Create the shortcut on the desktop, right click the shortcut, and set up a shortcut.