A blog is a personal website to which a person or group can record opinions and information on a regular basis.
The World’s largest education blogging platform, focused on teachers and students with educational support and features
The original blogging platform, now owned by google, offering blogs to anyone. A wiki is a website developed by a community of users.
A wiki is a website developed by a community of users.
A free wiki host providing community wiki spaces, visual page editing, and discussion areas.
PBworks is another wiki service that provides more folder capabilities, but isn't quite an easy to set up.