Firefox Live Bookmarks
I just downloaded the Firefox 1.0 Preview Release. A new feature called Live Bookmarks allows you to subscribe and read RSS and Atom feeds in your bookmarks. A button appears in your status bar to let you know there has been an alternate source detected and the MIME type is supported by Live Bookmarks. A blue folder appears in your bookmark folder with an individual bookmark for each item or entry in your feed.
I like the placement of the icon in the status bar instead of in the address bar like Safari RSS. Another branding win for the RSS format as well. It is good to see alterate link tags being used. Features such as Live Bookmarks should help motivate site developers to include more machine readable information in their code to allow for easier user access.