Nuno pointed me to
del.icio.us, a social bookmark manager that allows people to post their bookmarks, categorize them using keywords and browse other peoples bookmarks.
You can easily find who else linked to your bookmarks, what interesting link other users have on a particular subject, popular links, etc ... And it also has RSS feeds for several bookmark lists (personal, category, popular, ...). Nuno also recomended this nice
bookmarklet to use with del.icio.us that stores your keywords amongst other things.
You can find me there at
http://del.icio.us/arestivo (still only a few links)