WCF REST Service Hosted in Azure Service WebRole: AccessControlService?

Question

Im working in a project providing rest services on the azure pllatform. The service is consumed by a iPhone client, this is one of the big reasons for choosing the rest approach.

We want to secure the wcf services with AccessControlService(ACS), using identity providers like google and liveId. I have now spent more than a day researching and trying to get it to work, and the lack off information makes me wonder if it even is possible. I have among other things tried configuring the role with the Add STS Reference tool from Windows Identity Foundation(WIF).

So i guess my question is: Is it possible to secure the service using AccessControlService(ACS)?

Also if this is not possible, do anyone know any way of achieving the same functionality i.e. ACS securing the WCF service (oAuth not an option) users logging in with live gmail or other well known identity provider.

Dont have web.config file or others on this pc but can get them later if anyone wants to have a look.

Thx