According to an article in the business section of my newspaper, written by Dana Hull, mecurynews.com, ChargePoint (11,000 charging stations) and ECOtolity (4,000 charging stations) are collaborating via a separate service they call Collaboratev, which will allow for charging at an of the two companies stations and billing across both networks. They will also share data on where each charging station is located.
It doesn't help me any, as I am stuck with "level 1", but it might help you.