Is anyone familiar with the practice of lucid dreaming?

For those who aren't, it is the state of awareness of the dream state while in progress, with full "consciousness" of it while engaged in the dream. In a way that enables a kind of astral travel, within the dimensions of the non-physical. Contact with spirit beings is common, as well as the gain of knowledge, and realities previously unknown, with relevance to the material world.
If trained, near omnipotence in the dream worlds is possible.

I haven't been studying it for that long, it can be a pisser to entrain.
It was a major suprise when I found it is an actual mental/psychic/religious dicipline, I'd been encountering it on and off alone since childhood.

I'm curious how many other practitioners there are of this..