Hello! Thank you very much for taking the time to give your feedback, it's very appreciated. Sorry for the wait, I've been out of action for a few weeks now.
In the four (?) years NNF has been up, the total number of spam posts we've had is probably < 50. This is for two reasons: 1. NNF uses a novel anti-spambot technique and 2. It's a tiny forum no one is ever going to notice. Even forums with registration & e-mail confirmation get spammed; you can never stop the humans that get paid to spam so you have to have a multi-level approach.
We're just discussing the possibility of new systems to improve on what NNF has for managing content & spam. I'll give more detailed responses on that thread here: http://forum.camendesign.com/lets-rewrite-nononsense