Forgive me if I sound pretty ignorant (because indeed I am of this issue), but I'm curious to know if the d20 logo is really worth all that for you companies to forgo the freedom of going OGL. I mean you can pretty much do anything you want besides plagiarism if you go OGL: discuss character creation, make your own rules that may seem "parallel" to D&D's, and just about everything. I guess the question is, "Can you go OGL and still refer to monsters in the 'MM' and talk about skills and feats in the 'PHB' without specifically mentioning 'MM' or 'PHB'?" I'd appreciate any enlightenment from the d20 companies out there?