20 great Firefox extensions By Jason Meserve

#12 del.icio.us Firefox Extension
What it is: Quickly tag pages for posting to and access bookmarks from your del.icio.us account without having to open another window or tab.
Why you should use it: Save as you surf with ease. You can add a description, notes, and tags to the page before saving it. You can also search both your own bookmarks and the entire site simultaneously.
Where to get it: Click here.