Please read the FAQ before asking questions on the mailing list or IRC channel. You'll sound smarter and the responses will be much more helpful. Plus we want Igor working on Nginx, not answering simple questions over and over. ;-)
Mailing lists are the most popular way to discuss Nginx configuration and development. You can subscribe to the mailing lists or read the mailing lists archive at http://nginx.org/mailman/. The Russian language list is considerably more active, although you might want to bring Google Translate to keep up.
There's a forum with mailing list integration at http://forum.nginx.org.
The Nginx Planet is a great way to see what people that love Nginx are up to. Sometimes they like to discuss ways to make Nginx work better or how to build modules.
Bug reporting and feature requests
Bugs and feature requests should be submitted via Trac.
[OBSOLETE] See the Feature Requests page.
We also need people to review the changelog and make sure new features are properly documented in this Wiki.
Finally, if you find holes in the documentation (this wiki), please note them on the documentation requests page, or better yet, help fill them! If you get help on the mailing list or on IRC, please help others by updating this wiki.