Steve I have only just got my E-book reader and still think the catalogue is a great idea, however, I think the main problem lies with the Forum, I can work my way around a forum but found it nearly impossible to find the link for the catalogue, I pointed a few people to the forum for the list but they had difficulty finding it.
Maybe it would be a good idea to have a separate email address posted on the book section for people to ask for ebook and named people only to moderate and send the links. this maybe would take some resposiblity off your shoulders.