Smart Bookmarks Bar
Smart Bookmarks Bar is one of my favorite add-ons to Firefox, and the lack of it in Google Chrome is one of the reasons that I have hard to like that browser.
This add-on hides your bookmarks’ names on your bookmarks bar, and shows only the favicons. You can also choose to show an bookmark’s name when you hover over its icon.
This is really useful and makes it possible for you to have dozens of more bookmarks on your bookmarks toolbar. I have almost 30 bookmarks on my bar (after some cleaning) and I can’t imagine how it would be without this smart add-on. You should definitely check it out!