In a post to the official Digg blog, Kevin Rose has announced a new Digg extension for Firefox 3 that incorporates a toolbar and notification system into the popular browser that should appeal to heavy and casual Digg users alike.

In a video introducing the extension, Kevin Rose says that its main purpose is to get a feel for what features users would like to see incorporated into future releases. The extension was developed for Firefox 3, but users can download a Firefox 2 compatible extension here.

Small notification messages now appear in the bottom right of the browser window, displaying updates on topics you’re covering along with your friends’ recent activity (you can specify what events you’d like to receive notifications for). The collapsible toolbar includes a counter that indicates how many Diggs and comment the current page you’re browsing has received, and includes a “Digg It” button that allows you to submit and Digg stories without having to visit the site.