I use a lot of different sites on a daily basis (Del.icio.us, Flickr, Vlogdir, Yahoo, Tribe, etc), but I hadn't heard of OpenID until you mentioned it here.
Sounds like nice idea in theory. Have you set up a practice "account"? It would certainly be nice to make it easier and more transparent to log into and use SITO. The whole three-letter naming scheme doesn't have much use anymore, now that we're all database driven.
Doesn't seem like a top priority task, but if it's easy to implement... why not?