With your work in Web 2.0 based learning I recommend you take a look at Wiziq's virtual classroom and authorstream's power point presentation platform. Both are web based, have a bunch of features, and free basic service.
Day one of presentations pretty good.... couple of fantastic sessions ... picked up lots of tricks and tips... shall pass them on when I get all my info organised... Two days of workshops now so can get really stuck into things...... ran into Ian (baird??) from Murrumburrah (HS I think)
I focus on Web 2.0 apps in the classroom - feel free to check some of my sites.
And I´ve created one of the biggest groups on CR 2.0 called DigiSkills with 457 members now. It is about digital teaching methods - would love if you decide to join too.