Xmarks is the #1 bookmarking and open tab add-on. Keep your bookmarks, and open tabs backed up and synchronized across computers and browsers. Mobile phones with Premium access. Utilize LastPass to sync passwords!
Session Manager saves and restores the state of all or some windows - either when you want it or automatically at startup and after crashes. It can also automatically save the state of open windows individually.
AiOS lets you open various windows as sidebar panels, and quickly switch between them. So it put an end to the window chaos! In addition to bookmarks and history it opens dialogues such as downloads, add-ons and more in the sidebar.
Makes your Bookmarks Toolbar appear in multiple rows.
For Firefox 4 use: Multirow Bookmarks Toolbar Plus, available here:
InFormEnter adds a small, clickable icon next to every input field in a web form, from where you can select the item to be inserted - no typing required.
Enable multi-color highlighter and post-it notes as your reading aids; Capture the whole page or any portion to share or archive; Save everything online to allow access anywhere. See Youtube http://bit.ly/g5GvDw
TabGroups Manager helps to classify and organize tabs by dividing them into Groups. Because tabs become easier to manage, you can never have too many! TabGroups Manager is ideal for tab power users.
The Ultimate FaceBook Enhancer! Instantly add many tweaks to Facebook.com including: Large Images on Hover, Emotiocons, Select All Friends, Styles, and much more. A must have for Facebook users.