You might try the following web site:
http://bookweb.cwis.uci.edu:8042/AdamsHome.html
It is an exhibition of Ansel Adam's photography, not a museum store,
but it gives one the opportunity to purchase posters, prints, and even
make a donation to the host museum. This use of the web might
especially be a boon for the smaller museum, providing both
unprecedented exposure and perhaps some additional financial profit.