I hadn't been too clear on OpenID but a week or two ago I listened to a recording of a talk about that explained it well. I can't find it again, unfortunately, but you can take my word for it that it was pretty good.
Is OpenID being used in libraries? It struck me that it could work well for library systems that share resources: two systems that are part of the same consortium or provincial/state system; two neighbouring public systems that let people from one borrow at the other; academic libraries that want to make it easy for visiting profs and grad students to get temporary access to online resources; etc. Say I live in Lower Mowat but one day I'm in Upper Mowat, in the next municipality (or county, or whatever) over, visiting my tailor. The two library systems are separate but share their resources. I pop into the library to update my Twittering friends on my inseam measurement. I don't actually have an account at the Upper Mowat Library, but I log in to one of their computers using my Lower Mowat-supplied OpenID identifier, and the Upper Mowat system recognizes where I'm from and gives me access to everything. Bill -- William Denton, Toronto : miskatonic.org : frbr.org : openfrbr.org