Nick was talking about wah wah pedals last night, I thought I would look it up this morning (working hard you know).
I found this page which goes into depth about the workings of wah circuitry. Mostly over my head, but seems worthy of study.
http://www.geofex.com/article_folders/w ... wahped.htm
This is the kind of stuff I would like to see workshops done on by those in the group that have the knowledge (or perhaps those that want to get the knowledge and are willing to do enough research to put together a presentation).