Augmenting classroom lessons -- on-line.

It's been three years since I started tutoring students of the CUCG Summer School (run during the long vacation). It's been an experience: ups, downs, in-betweens, but I'm always thankful for the opportunity.

Personally, I think the stress these students go through is immense and overwhelming, and often does tell on their grades. The headache for me these years has been to find a convenient way to augment the classroom lectures. The fastest answer of course, on-line classes.

Before I had this urge, e-mails were mostly used to exchange, share lecture notes, assignments.
This year however, a new approach was used (or added). We created a group on Facebook, which afforded effective communication as a number of people can chat at the same time, thus exchanging ideas and helping one another. Another group (or Circle) was created on Google+ and that took us even closer to our interaction-oriented goal. Unfortunately, we never got to do a hangout -- connectivity issues. But I saw an improvement in the class, and that makes me happy.
Google Docs also came in handy as the class got a taste of how to collaborate using the service.
There's more room for improvement. The positive influence of on-line in education cannot be over-emphasised.

I would like to hear from folks who have fused on-line technologies in their classes: experiences, ideas I can use, and more areas I can explore.