We’ve tested quite a few bookmarking tools and how well they integrate into the Firefox Web browser: Diigo, del.icio.us, Google Browser Sync, Mozilla Weave and more.  The best has always been, and continues to be, the del.icio.us Firefox extension.  The extension’s integration into the Firefox Web browser is unparalleled and offers the following priceless, time-saving features:

• keyboard-shortcut (Ctrl+B) activated search-as-you-type functionality
  (this brings up the sidebar which brilliantly disappears as soon as you find what you’re looking for)
• the ability to add both tags and notes to your bookmarks
• synchronization with your del.icio.us account (meaning that neither a specific browser or the extension itself are necessary to find your bookmarks - just hit http://del.icio.us while you’re on the road and login.)

This is one of the few tools that I use every single day and, unfortunately, it’s core functionality became broken when Mozilla released the beta versions of Firefox v3.  It’s taken quite a while but Yahoo! has finally released an updated version of the extension yesterday afternoon:
http://tech.groups.yahoo.com/group/delicious-firefox-extension/message/2204.

I found it took a bit of maneuvering to get to the installation file so I’ve gone ahead and posted it on our site for you to download.  Just save the file, open your Firefox Add-Ons window and drag-and-drop the .xpi in there.  The installation process will proceed and you’ll be prompted to download the update.

By the way, kudos to Yahoo! for listening to their users and pushing out an update to this extension.  The final version of Firefox 3.0 hasn’t even been released so they technically didn’t "have" to release a version yet but they realized there was a huge demand for it.  Are you paying attention, Google?  I only ask because it’s been almost two years since Google Browser Sync was released and very little has been done to keep it updated.  In addition, you’ll notice that almost every post in the Google Firefox Extensions newsgroup remains unanswered.