The latest version of Google Chrome browser now allows users to pin tabs. Just right-click any tab and select Pin Tab. This feature was one of the many that urged users to migrate to Chrome, but now you can finally get it in Firefox too. Pin Tab is the new add-on for Firefox that allows users to pin any tab during a session.
Update: Pin Tabs for FireFox has been discontinued, because FireFox now natively supports the Pin Tabs feature.
To pin it, right-click the tab and select Pin tab or you can Ctrl + Click the tab. Once a tab is pinned you will only be able to see the favicon. Obviously you will only pin those tabs which you are familiar with.
The major benefit of pinning the tabs is that it saves space. If you are like me who has around 20 tabs open then pinning does actually help.
The only downside I could find was that these pinned tabs are not permanent, they last for only one session.