TechSoup has an article on:
Designed to help like-minded individuals and organizations connect and share information, social networks are showing promise as low-cost, high-impact marketing channels because they are both highly visited and highly targeted. In particular, many nonprofits are starting to set up profiles on social-networking sites like MySpace to keep “friends” up to date on the latest activities. These friends then invite more friends to join the group and so on, ultimately allowing the nonprofit to reach people well beyond its original circle.
I have to admit – I have yet to sign up and try MySpace – mostly because I don’t have time to maintain another site – but I guess I should give it a whirl so I can learn more about what’s involved in setting up a page.