Britt Bravo posted on her blog Have Fun Do Good a great guide to how to make your blog support your organization's cause. There are some great tips in here, including this one:

"When you are creating your press list, be sure to search on Technorati and Google Blog Search to find bloggers who are writing about your organization's issues and send them your press release as well."

Check out her previous blog posts as well. She has a great post on how to start a non profit blog, if your organization is in that phase.

~Yvonne Archer, Green Media Toolshed