An interesting project is starting up to help pre-service teachers establish their own personal learning network. Boringly named The pre-service teacher's network, it is an awesome idea.
While mulling over David's How to get rid of the lecture, I'd come to the conclusion that the highest priority should be in establishing contact points between students. The lecture not only provides information for students, but also binds them into a shared experience of time / place / content. Without that common binding, it's very easy for students to feel lost in the content and become overwhelmed. What is needed is a simple way to connect to another student travelling on the same learning journey. Really simple. Like looking around the room or nudging the person next to you simple.
PSTN has the opportunity to be just that. A simple way of nudging someone to see if you're on the right track. The learning journey isna't a specific class, but a profession that cries out for additional support.