CNN has an article about Corporations blogging. Much of what they talk about in the article is directly applicable to non-profit organizations. The Berkman Center also has a reaction from David Weinberger, where i got the following quote.
Question: Why aren’t there more customer-facing corporate blogs?
David Weinberger: Companies still too often see blogs primarily in terms of risk – someone will blab a secret or whine about a boss. In fact, blogs are ways for people who share interests to form relationships more human and intimate than what marketing departments can manage.
Now substitute “organizations” for the word “companies” and I think it holds up well for museums and other non-profits.