well, I really only have 3 - bookmarks, delicious bookmarks and the google toolbar. I used to be a huge stickler for screen real estate, but since i haven't been without at least 2 monitors at < 1680x1050 for a few years now, i don't mind them. Surprisingly, i use the Google toolbar least of all (other than for... well, searching Google).
The bookmarks toolbar is a crappy sort of workaround to an idea that Jamie & I had a few years ago to have a home page with all the links to your "daily" sites. Opera's "dialpad" or whatever it's called is a good version of this, though it's only got 9, and IE's is a little better, but it and Chrome's are both based on popularity, not choice, and i don't want that flexibility taken away from me...
the delicious toolbar is fantastic, because 99.9995% of the time when i post something to delicious it's because "i want to read this, but i don't have time right now"... so when i have time, i can just look up there at the last 9 or 10 things i've posted, and poof.
makes me wonder, would a "link-o-matic" FF add in be cool? would anyone use it? heheheh