Adam Frey, one of the three founders of Wikispaces, has informed me that Wikispaces is lifting its cap of 100,000 free and ad-free educational wiki-sites. (The company had just about reached the 100,000 number that it had earlier set.) Anybody who wants a wiki-site for 100% educational purposes can now get one.
But make sure that you are one of the next 150,000!!!