I setup a registered topic channel on Freenode IRC. (http://freenode.net)
IRC has been a popular chat method for decades, and Freenode focuses on many engineering related channel topics. IRC is also relatively anonymous and free of marketing.
Feel free to join the channel to chat or discuss questions about anything .NET Micro, Gadgeteer, the Fez parts or other related topics .
Popular chat apps are available on all platforms for free. mIRC, Colloquy, xChat, IceChat (written in C#!) are a few.