I am sold on this one. What a wonderful access to resources that will keep me a "life-long learner." I thank everyone who has contributed items I know I will either link to or use. I tried the recommended search of "School Library Learning Web 2.0", in each of the tabs provided. I got so caught up with checking out the results, that I can not be definitive right now about the differences. I'll have to do it again when it is not so late at night.
As for tagging, it sure does show how standardizing (subject heading) helps, as I found myself wanting to use the same tags other people used. Is there a lesson in there on keyword vs. subject heading/descriptor?