The guys at del.icio.us have launched a “very preliminary del.icio.us firefox toolbar at http://del.icio.us/toolbar/ :
The button icons are placeholders and a product of Joshua’s creative fury. If you bring up the ‘customize’ toolbar palette in firefox, you can rearrange, remove or place the buttons on on any other customizable firefox toolbar.
The icons are very basic, but somewhat charming. There’s not an awful lot going on, but the ‘about’ button is a useful addition, listing all the other people who have tagged the page you’re viewing.