Identity (directory) with No hub and No Centre via the amazing @Kim_Cameron
Source : http://www.identityblog.com/?p=1220
“In the last frame of the diagram, any of the directories represented by the blue symbol could be an on-premise AD, a Windows Azure AD, something hybrid, an OpenLDAP directory, an Oracle directory or anything else. Our view is that having your directory operated in the cloud simplifies a lot. And we want WAAD to be the best possible cloud directory service, operating directories that are completely under the control of their data owners: enterprises, organizations, government departments and startups.”