Firefox is such a powerful and diversified tool whose implementations can be from a simple browser and extends to a powerful web development and troubleshooting platform. Its customized addons enables us to do virtually anything. I have listed below some of the social networking and bookmarking related extensions:
- StumbleUpon - StumbleUpon lets you "channelsurf" the best-reviewed sites on the web. It is a collaborative surfing tool for browsing, reviewing and sharing great sites with like-minded people. This helps you find interesting webpages you wouldn't think to search for.
- Foxmarks Bookmark Synchronizer - If you use Firefox on more than one computer, you'll want Foxmarks. Install Foxmarks on each computer, and it will work silently in the background to keep your bookmarks synchronized. As a bonus, log in to my.foxmarks.com from any computer anywhere to access your bookmarks.
- del.icio.us Bookmarks - This extension integrates your browser with del.icio.us (http://del.icio.us/), the leading social bookmarking service on the Web. It does this by augmenting the bookmarking functionality in Firefox with an enhanced experience.
- Clipmarks - With Clipmarks, you can clip the best parts of web pages. Whether it’s a paragraph, sentence, image or video, you can capture just the pieces you want without having to bookmark the entire page.
- Tab Mix Plus - Tab Mix Plus enhances Firefox's tab browsing capabilities. It includes such features as duplicating tabs, controlling tab focus, tab clicking options, undo closed tabs and windows, plus much more. It also includes a full-featured session manager with crash recovery that can save and restore combinations of opened tabs and windows.
- Yoono - Yoono instantly suggests similar sites, blog notes and people sharing the same interests while you are surfing, for each page you open. Zero effort required - no more tagging, typing keywords or changing interface. Let Yoono bring you the best that others have discovered.
- BlueOrganizer - The blueorganizer is smart browsing and personalization technology for Firefox. It makes the browser aware of everyday objects like books, movies, wines, restaurants and much more. The blueorganizer helps you automatically collect these object from many popular sites, manage them and instantly find related information.
- Jeteye - Jeteye is a unique Web-based application and service that is designed for the next generation of enterprise and consumer use of the Web. Jeteye changes how we interact with the web, in an era where communication and social computing are more powerful than ever.
- Bookmarks LinkChecker- Updated from v0.6.8, extension 'Bookmark Link Checker' detects updated, redirected, and broken links in your bookmarks list by adding icons within the drop-down bookmarks menu.
You deserve kudos for putting together this great list of firefox ,addons... foxmarks was especially very useful.