Connotea is “an experimental bookmarking service for scientists.” Created by Nature Publishing Group’s New Technology team.
“Save, share and recall anything you find online.”
“del.icio.us is a social bookmarks manager. It allows you to easily add sites you like to your personal collection of links, to categorize those sites with keywords, and to share your collection not only between your own browsers and machines, but also with others.”
From Openly Informatics, a Firefox extension for OpenURL and Google Scholar.
“Folksonomies – Cooperative Classification and Communication Through Shared Metadata”
“Mycroft project provides a rich collection of Search Plugins for Mozilla-based browsers.”