I would be excited to see scientists contribute to student-run science blogs! They could comment to student posts or submit their own post and converse with students. A conversation could continue with a video conference or an actual visit to the school. My students work so hard on their blog and would benefit greatly from input from scientists.
Perhaps we can get some of the science teachers with experience in using blogs in classrooms to bring their students to talk to us at the ScienceOnline’09 in January.