Once you build up a large list of bookmarks, keeping track of them all can get a little messy. To stay organized, you can assign tags to your bookmarked sites: just double-click on the star icon and you’ll be prompted to enter your tags.
You can tag a site with as many terms as you want (be sure to put a comma between each tag), and then easily find the sites again by typing that tag into the location bar. For example, entering “travel” into the location bar will bring up all the sites you’ve been bookmarking as part of your vacation research.
Ding ding ding. Sign me up.

Isn’t that anti-social?
You should be bookmarking in a super awesome social bookmarking engine such as Lotus Connections Dogear
Hey Luis! You know what I want? I want Dogear, Delicious, Digg, etc. to simply slurp my tagged bookmarks from my browser, based on simple settings I choose. I expect that’s coming, or is already here for one of more these tools.
Interesting. I know we can already import local bookmarks into Dogear, for example (probably the same with digg and del.icio.us), so now it’s a matter of using the tag data from FF3. I can’t believe someone isn’t coding this up right now.
Meanwhile… I do like the ‘Most Visited’ feature of FF3. I expect that after a while I’ll be able to delete all my bookmarks from my toolbar (which are the ones I use on a day-to-day basis) and then just use the ‘Most Visited’ and Dogear to find stuff..
It would be cool to if a user could seamlessly access their (and others) social bookmarks straight from their browser’s bookmark bar. The FF sidebar plugin is cool and all, but regular Jane and Joe User won’t adopt it very fast, if at all.
Hmmm. Social bookmark engines serving bookmarks to the browser’s bookmark toolbar, with no setup, no configuration required on the user’s part. I like it!