I found this article in the Chronicle of Higher Education a few months ago and then forgot about it until I stumbled across it again recently.The author's list for a perfect archive included long hours, grants of any size, silence, incadescent (not fluorescent) lighting, good security, photocopying (and allowing one to use a credit card to do so), plugs for prolonged laptop use (and Wi-Fi would be even better), along with complete finding aids for all holdings available online, comfortable seating, ambiance and form (including windows letting in natural light), and creative programming such as film screenings, talks, workshops, and seminars in its after-hours.
The only thing I would add is a policy allowing the use of digital cameras (taking copyright issues into consideration, of course).
