OpenID and my schema

I’ve recently decided to use OpenID to let users log in to my site
instead of old fashioned account creation. They’ll be able to add a
small amount of personal details (about three things) to their
account, and post messages in the site BB. I have an openid_users
table which stores the personal details in. Obviously I’ve got
validates_uniqueness_of :openid in the model, and I’ve linked it as
required to the BB tables. Do I need any other tables or anything, or
is that it?