My tutorial at OSCON2004, "Extending the Database with C"
(http://conferences.oreillynet.com/cs/os2004/view/e_sess/5134),
has had low signups to date. O'Reilly asked me to write an article that
they could publish on their ONLamp site in order to (hopefully) drum up
interest. The article is now published and can be found here:
http://www.onlamp.com/pub/a/onlamp/2004/06/28/postgresql_extensions.html
Joe