Thanks to a heads up from a colleague, I and my class have been messing around with pbwiki at http://www.pbwiki.com/ Here you can make a free password protected wiki they say, "as easily as a peanut butter sandwich". Actually it is pretty easy and some of my grade 3/4's have taken to it like a duck to water. You can see their 2 day old handiwork at http://middlej.pbwiki.com/ .

What's a wiki? It can be just about any sort of web based collaborative exercise you want it to be. We are sort of making a glossary based exploration of minibeasts in our wiki, check it out.