Found this recently at wikispaces. Don't know much about it. This would definitely be a short-term solution to something that we're planning for the School Portal project to address with a long-term solution. But, in the near-term, it seems like a better option than teachers hosting their pages with 101 random different providers. So, I'm sharing it here in case it sparks any interest.

Back in January 2006, we decided to offer our Plus Plan to K-12
teachers for free. We didn't set out with a grand strategy, just an
interest in helping teachers with our easy to use wiki? technology.

Over 10,000 educational wikis later, we've heard
countless stories of excited students and empowered teachers. They've
told us about their collaborative essays, group study guides, online
lesson plans, and classroom notice boards coming alive on Wikispaces.

Now we're taking the next step - we want to give away 100,000 free K-12 Plus wikis. That includes all the features and benefits that normally cost $50/year - for free. No fine print, no usage limits, no advertising, no catches.

We hope that you'll read on, try a wiki at your school, and help us spread the word.

- Adam, Dom, and James