Or a mailing list?
Well here's and article that explains some of the reasons Cause Effect: Why social networking is important for non-profits:
Social networking is a fantastic tool for non-profits because it's relatively inexpensive, it allows for an ongoing, two-way dialog between the organization and the people it serves, and gives passionate people a platform to talk about causes and organizations that are important to them.
This blog is just running in a trial phase. I set it up to try to show why SAFCEI should have a blog. If anyone reading this is involved in environmental NGOs, perhaps you could say why you find blogs useful (or not, as the case may be).