I've been listening to the discussion about exclusivity, and thought I'd chime in. What I might have to say may even be heretical for those who are hungry for main-stage (or as some colleagues have put it, "Big Name" presses).
I think that some degree of respect is in order for groups like LEONARDO who have marvelous legacies and have honestly done fairly well by promoting art & tech. I also understand the concern for exclusivity in "big press" publications as well, but I take a bit more of a Lessig-like approach.
Being that I am part of a team that (still) puts out a scholarly publication (albeit less frequently). I still stand behind Intelligent Agent's model of exclusivity for one month, then republish with a polite request to mention us in further publications. I think it's a good way to share, while giving some precedent to the host institution.
Here comes the heresy. Although I have published with MIT Press on a number of occasions, and many others, this is not to say that I may not web-publish the articles and chapters that I have published in print. My rationale is that atoms are still desirable, and who really wants big binders full of PDF's? In addition, most of my colleagues still copy chapters, etc. There are endless rationalizations.
Bottom line is that I feel that if you want paper, you will buy paper regardless if it is online or not. I love my library, and it's wonderfully easy to pop a book off the shelf. Will a press suffer if I place my chapter online? Academic presses are small enough that I think they will not suffer that badly, or even possibly have counterbalancing sales from greater awareness of the work.
But on the other hand, I also realize that a lot of effort goes into these books and publications, and although I may re-publish, I feel that it's also unfair to re-publish the material too soon after initial release. In other words, give the publisher a little break, and then consider to do "what thou wilt", with a note of the initial publication. In this way, the reader is given a little plug for the original publisher, and the material goes out in multiple channels.
I agree that strict exclusivity is anachronistic, as I feel that as long as there is a cross-mentioning, there is mutual benefit. I love LEA, and all of the Leo publications - I think they do a great job. However, I feel that a "gentlemanly" (another anachronism) dissemination of the information is also of little harm, as those who want the book or materials will want it, regardless.
Therefore, I hope that others might agree that publishign with exclusivity is perfectly fine, but reserve the right to put a copy on your website. That is, if someone wants to read it, great, but also perhaps do not post it across all your blogs...