NetGhost, of Halocination, sends word of a Halo NetClub:

It's not just a message board though, it's also a chat group, poll system, etc. The best part is that if you use NeoPlanet (w/NetClubs) as your browser, it allows you to access other people in the net club the same way you would with an instant messaging program. Hopefully we can get a strong Halo community online, I KNOW there is a large community out there, let's all get together.

Sounds interesting, though it may be a bit too early for such ambitious community undertakings. Nevertheless, swing by and take a look.