Circles seems like the Google+ equivalent of labels in Gmail or tags in Reader. You can easily tag a thread or user with one or more descriptive labels. I don't

Circles seems like the Google+ equivalent of labels in Gmail or tags in Reader. You can easily tag a thread or user with one or more descriptive labels. I don't find that a lot of work. Facebook, in comparison (last time I checked), makes you go to the group to add/remove people. Major pain to manage groups in FB.