I am a happy blogger. Using the U-Think platform, I involved a group of graduate students in co-authoring the Research and Issues in Science Education: Challenging our Minds and Methods (http://blog.lib.umn.edu/meyer179/umdenvironmentaleducation/) blog for a course on science education research. Though I learned a few things and would definately craft the assignment a bit differently next time, it worked very well. The students used the technology with little effort. We were able to share the blog with EE professionals across MN. And I learned a lot about blogs through the process.
Around a year after our son was born, my wife and I also used Google's Blogger (http://www.blogger.com/) to create a family blog. With parents in Oregon, Philadelphia and various points between, the blog enables us to make quick and frequent updates. It also provides us a sort of free-organized archive of family memories, and the ability for family to participate in the conversation.
From these experiences, I see a lot of potential for blog technology in Extension programming. They are so easy to use for both staff and participants, inexpensive in both time and $$, and fluid to many uses.