Have you considered adding certain minor/easy perks for membership? Sometimes they help push people over the edge into supporting something they like anyways.
For example, the Linux Foundation has a few deals with vendors for discounts and membership comes with an @linux.com email address which automatically forwards to another address for you. Maybe you could work with some of the bitcoin vendors for discounts on their services to your members or offer an @bitcoin.com email forward.
good plan, could be a pretty good promotional tool if done right (can't help but be reminded of the early days of Gmail when it was invite only). Although, who knows when the foundation will have the resources to run a busy e-mail server, I wonder if it's anything close to their top priority right now.
How about this: I seem to remember reading about how Gavin Andresen wants to eventually implement a secure way of mapping public keys to a sending address that reads like an e-mail address. In the event that that is achieved (and depending on whether the implementation uses the <username>@<domain> convention), perhaps the foundation could take out ownership of the bitcoin.org domain, or whatever domain they deem most appropriate, and then provide those addresses exclusively to foundation members.
I have no idea whether the software engineering challenge would permit such a thing, maybe someone from the dev team could enlighten us.
