Christian Heilmann offers us Dishy, a JavaScript REST API for talking to del.icio.us. Taking full advantage of del.icio.us' JSON format and the script element, Dishy doesn't need a server-side proxy. Its a useful helper class for easily getting information from del.icio.us.
Gez Lemon reviews Christian Heilmann's recently published book. Its a thumbs up, and recommended for developers working with standards and accessibility, regardless of their JavaScript level.