http://www.webaffiliatecreators.com has an article submission that allows users to share content with other users.. basicly.. we just let people add articles for a backlink, and other people come along and use them.. pretty sure thats how CAP’s program works too..
So basicly, just build it, advertise it, and ppl with an interest will contribute.. once ya have it up, hit me up, I might just contribute some myself 
~LadyH