The "Things" I liked best were Flickr, Facebook and LibraryThing. Things I like least were probably Twitter and Ning. The Systems side of me gets nervous with too much information out there about me and not being able to control who has access to it. My daughter also does tech support, and I could not talk her in to signing up for some of these things to practice with me. Facebook, at least allows some minimal control--only your friends (and their friends) can actually read your posts. I also like the way Facebook pushes info to your email.
There seemed to be a lot of duplication--rather like everyone, Google, Yahoo, Microsoft had to offer their own version of a "thing." I guess that makes sense since we have a gazillion browsers.
One of the things that I saw at the SD conference in Dallas was ChiliFresh. ChiliFresh is Beta testing a new product which at this point is called "Connections." Its a good simple way to integrate Web 2.0 things with your catalog and yet keep some control over what is ultimately visible to the public. We were invited to participate in the Beta testing, but had to decline because we do not have a test server. Bummer!
Thanks again for a great experience!