I had some ideas about how bookmarks should work in browsers. As I type this, they will become a permanent record in slashdot.
First, and this is starting to be done better, but not always fully, but browsers should use the favicon.ico next to the bookmark text.
But even better than that, would be if the browser took a self screen shot of the page when you bookmarked it, and then when you are browing through your bookmarks and put your mouse cursor over the bookmark, it displays the thumbnail sized screenshot of the web page.
Web browsers should keep track of which bookmarks you click on the most and display the top 5 or whatever in a "recent" or "most clicked" category in the bookmarks.
This next idea I think is being implimented. But you should have bookmark folders which in fact are an RSS (speed) feed, where all the links in the folder are actually items in the feed.
Another idea is to be able to bookmark a history. So when I go to a bookmark, I can also (optionally) get the back and forward history that I had when I bookmarked the page.