how about this... you make a wireframe. For those who don't know what a wireframe is, is basically a mockup of the site with JUST the content and no graphics. This allows everyone to see the information flow and the idea without getting too caught up in the graphics initially. Then once that is mutually agreed upon, then move to the next stage, the visual look and feel, allowing input from anyone who wants to be involved. Then once everyone is in agreement and equally excited about the concept, you will have created enough excitement and mutual personal investment through the process that everyone involved will volunteer their time to see it through.
