If we wanted to really increase traffic to this site we would do some of the following:

Facebook,Twitter page - with links back to the main site
Posters on here would also post on other online forums having links back to our site in their signature and referncing articles they pulled off this site
Create online articles on a different webserver/domain taking about pickup etc and have references back to this forum.

this is all classic SEO work - wont get you penalised by google and will make google give you credibility,
you will not only get new blood to the forum who hapen across all your pages as above-- BUT you`ll also get ranked much higher in search engine results
i dont know how you got penalised by google but doing thinks like createing blank pages with puaforum.co.uk etc in backgroudn colour txt will!