Classroom 2.0 - the Social Network for Teachers - well worth your time - collegial, informative, enriching
http://www.classroom20.com

The "unconference" without walls - happened in October but was asynchronous - view the videos and presentations on your own time - and all still up for viewing now, as is the 2006 conference
http://www.k12onlineconference.org

David Warlick is an educational technology leader who knows teaching and learning as well as how new tools can expand the classroom
http://davidwarlick.com/2cents/

Will Richardson's blog on Web 2.0 for the classroom is always worth the time
http://weblogg-ed.com/

Vicki Davis is a teacher and somehow finds the time to share her terrific ideas on using Wikis, Blogs and other tools with her students
http://coolcatteacher.blogspot.com/