A few months back, we kicked off some work with St John's University on integrating Exchange Labs with their deployment of Luminis.  In summary, St John's wanted to enable students that were logged onto the Luminis portal to be able to bring up their email in OWA without being challenged for authentication on our service.  A screen-shot representing what is now in place is below, and a site dedicated to the project, managed by St John's, can be found on our CodePlex shared source site here: http://www.codeplex.com/LuminisLiveSSO.  You will find sample code, prescriptive setup documentation, and a place to ask your questions.

If you enroll in the Exchange Labs program, you will also have access to additional documentation on SSO.

Enjoy!

Jonny