Firefox's Bookmarks toolbar is invaluable. To allow for more links and more efficient use of real estate, I usually kill the name of the bookmark, as the favicon is more than enough for me to be able to know what site I'm clicking on. However, one annoyance I've had is with Firefox's Live Bookmarks: the ability to add an RSS feed as a bookmark that is updated with the articles in the feed. Useful for browsing sites with lots of interesting content, like digg or headlines on the NFL, without having to wade through the pages. However, they lack favicon support, meaning they take up a lot of toolbar real estate.
Enter LiveClick, a Firefox extension that allows you to bring the joy of favicons to your Live Bookmarks, as well. While also offering a ton of micromanagement for these bookmarks, I really love it for the favicon support: it's automatic, slick, and lets that real estate stay valuable.
Now, if I could just figure out why some bookmarks actually pay attention to their site's favicons, while others remain blithely ignorant, I'd be styling.