In regards to the discuss we had with the K-12 Federated Identity and Access Management Taskforce on our August call, Stephan Papadopulos has shared a short 5 minute demo they developed in DC to describe how the DC One Card Digital ID can be easily used as a universal login to various web applications:
https://docs.google.com/open?id=0B5EYAYZhD4byb1dDWmpBWVAza28
DC has integrated an open source Access Management tool with their Identity Management System in the DC development environment. They also created several sample websites into which anyone with a DC1C Digital ID can authenticate.