Yesterday I sent a message to the Nginx list to announce the availability of my first module for that web server.
The module is used to do HTTP Basic Authentication agains PAM instead of using an htpasswd file; I wrote it because I wanted to authenticate against OpenLDAP and PostgreSQL and PAM already has support for that ;)
The code is available here and on the readme there are instructions on how to build a patched debian package with the module included.