Chrome: While the official Delicious bookmarks extension for Chrome is perfectly serviceable it's quite spartan. Felicious enhances the Delicious experience with in-browser display of tags, existing bookmarks and notifications.
The official Delicious bookmark extension is essentially just a little pop-up window of the Delicious bookmarking box hooked right into your address bar. Felicious offers a list of all your tags, your bookmarks, and it gives you an immediate visual indicator if the page you are visiting has already been bookmarked in the past — the little bookmark icon on the search book turns from black to blue as see above.
Felicious is a free and works wherever Chrome does. Thanks MPS!
Felicious [Google Chrome Extensions]