Came across diigo this evening and am converted immediately. Waiting for del.icio.us v2 and not hearing much detail or eta. One of the main problems I have with del.icio.us is the lack of a facility to securely share bookmarks with colleagues, diggo takes care of that and a hell of a lot more, video here tells you all about it:
unklerupert's knee
Werthers Original?
That is really great! Believe it or not, back in about 1998, the was a similar add-on for Internet Explorer (PC Only) which would do something similar.
So many companies got upset by people slagging off their sites in-situ that they got threatened big time and disappeared.