I posted a question at stats.se over a week ago (April 22 2013) about communicating database structure to a non-technical audience. It remains unanswered with multiple upvotes.
I suspect that it would be off topic here as a "brainstorming / idea gathering" question. But before missing out on the opportunity to tap this community for ideas, I would like to confirm my suspicion.
update: I have revised and reposted the question on this site: How can I show a database graphically?