Google Reader (1000+)

"Easy App Tabs helps you create and remove App Tabs, the permanently pinned tabs on the left side of your tab bar. Double-click on a tab to set it as an App Tab, or return it to normal status. The feature was left out of Firefox because Mozilla found that users were accidentally creating app tabs when they didn't want to.

Another smart and simple tab-focused add-on is Tab Badge. This add-on shows you an unread count on your social networking and e-mail sites as long as the number of unread messages is programed to appear in the site's titlebar. So, if your Gmail title is 'Priority Inbox - 10', the number '10' will appear in a red circle on the tab. While Gmail has the feature available as a lab experiment you can activate, this is a clever way to get it on all your communication sites."

Source : Google Reader