Thanks for the offer of the tool. I will need to talk to our Moodle technical folks and try to persuade them that this is something we should try.
"Open" is an evolving notion in my mind. I struggle with what parts of a course to conduct outside the Moodle shell with all its attendant privacy and identity protections. At the same time, I'm trying to make sure that my students become proficient in using Web 2.0 and social networking tools. Also, I'm trying to develop a learning community around the topics that will exist beyond the time limits of the course.
It seems to me we are trying to define an "open" space embedded in the intersection/overlap of formal courses and personal learning environments.