Re: "lecture preparation": a new form of active learning?

Its common in graduate school: we call it "graduate seminar".
The research students (including advanced undergraduates) take
turns making presentations. Usually about progress in their research,
or interesting ideas they may have encountered elsewhere.
Besides, think how easy it was on the professor if he doesnt have
to talk every time.

Our seminar was particularly agressive at evaluating each other's ideas.
You learn to prepare well and think on your feet fast. They negative
times can be disconcerting, but you get used it. We were a holy terror
at scientific conferences questioning others' results.