Look at the new web 2.0 features of MadCow
MADCOW on web notes is:
social annotation and icon taxonomy
sharing links, own files and comments
text annotation
image annotation
search engine
How it works:
MADCOW is a client-server application software enabling users to associate web notes to any interesting portion of a web page. In fact, while navigating the web with a standard browser (Firefox), the user can click on the bookmarklet "Post to MADCOW" installed in the bookmark bar and select a portion of text or an image in the page. A dialog window pops up where he/she can add his comment, attach any multimedia file of his/her choice, and chose one out of the 9 annotation types (comment, question, announcement, explanation, integration, etc.). The web note is automatically saved in the MADCOW servers, and can be retrieved in any further browsing session: when the user access the web page again, clicking on the bookmarklet "MADCOW Notes", it inserts an icon next to the annotated part; clicking on the icon show a preview of the annotation in a comic bubble. The web notes can be accessed also by other users, provided the author declared it as public in the 'create-annotation' window. This fosters cooperative work, as it becomes possible to start discussions about any topic, binding the web notes to the object of discussion. Note that an annotation can be annotated in turn, allowing threads in the discussion.