For quite awhile now I've been using del.icio.us for all my bookmarks, and one of the nice things about this is that it has freed up my Bookmarks Toolbar in Firefox. Lately, I've gotten into the habit of using the extra free space for a GTD approach to bookmarking. Here's how I have things set up:
I have a delicious tag favs for my most visited bookmarks, and I've add the feed for this tag as a Live Bookmark in my Bookmarks Toolbar Folder as the first item. These screenshots show how to set something like this up:
Tag your favorite stuff something like favs. Go to your delicious, then go to your favs page. Click the orange rss button in the Firefox address bar and choose Add RSS feed tagged "favs" as Live Bookmark. Make sure it's in your bookmarks toolbar and you'll have a nice little dropdown of these items.
Now you can use the rest of the real estate as a Bookmarks Inbox.
Any time I come across a link that looks interesting, I just drag it into my bookmarks toolbar folder. Then, when I have some free time, I go through all the bookmarks in my toolbar and either delete them or save them do delicious. This works especially well if you're on google ig, google reader, or some other page with a lot of links on it. Instead of opening everything in new tabs, I just drag stuff I might want to check out to my Bookmarks Inbox.