Del.icio.us is a site that will allow you tag or apply a keyword that organizes your bookmarks. For instance, if you tag bookmarks with Education, all will be organized under this tag or meta data. Further, you can share your tags/bookmarks with others which is where the social comes in. My delicious bookmarks are at: http://del.icio.us/kschaefer. You can see what I have tagged. You can set up and account and use this system to share bookmarks for your students instead of giving them a handout or a long URL to type in. Set up tags based on folders or topics that you teach.