Alik Levin, from the Access Control service content and documentation team, has written these great step-by-step instructions on how you can use the service for federated authentication using Windows Live ID and Google accounts in your Windows Azure ASP.NET application.
Read the step-by-step instructions, and find a number of great resources related to the Access Control service in these posts:
The capabilities of the Access Control service mentioned in these instructions will be added to the production service soon. In the meanwhile they are available for you to check-out in the Community Technology Preview (CTP) service in our LABS/Previews environment.
In order to use the CTP service just sign up here: https://portal.appfabriclabs.com/
To use the production service you can sign up to our free trial offer, just click on the image below and get started!