[Lazy_Perfectionist]

Alternatively, you could get some instant messaging/chat program that gives you a number as an identity, and allows you to assign an alias, such as Agartha.

For battle reports, you might be able to have a blog or livejournal that allows anonymous/guest posters where you can type in a name each time you post.

Personally, I like the idea somewhat of having to give away your identity to manage really quick diplomacy. There will be a cost to complete anonymity. And to encourage 'coming out', theres the whole bit about "what happens in Vegas" stays in "Vegas". The anonymity lasting simply for joining is enough to prevent a player from designing a specific counter. There could be a definite advantage to not proclaiming you've taken a slot at all- polls to keep track of numbers.

I'm not really familiar with instant messaging clients, so I don't vouch on accuracy. I think maybe IRC or ICQ just assign you a number and let you pick and change an alias to your nation. I do know there are some anonymous online chatrooms, though I haven't used any.

Alternatively, if there was a huge demand for super secret games, maybe there could be something done with a separate forum. A game could be started here, with some discussion going on, and the rest done on a forum where users have to register (to prevent spam), but doesn't display usernames.