I realized this morning that the "three teachings" of morality, concentration and insight seem to correspond roughly with the "outer," "inner" and "secret" teachings of Tibetan Buddhism. (Twenty-minute outline in this audio file starting at 51m30s.) Are they actually the same thing?

I think there may be something of a correlation, but keep in mind that insight meditation in most Tibetan schools consists of a great variety of practices, many of which are not very similar to vipassana or MCTB stuff. I'll do some research and get back to you - I'm taking a class on Tibetan Buddhism now so I have some good texts lying around.