Lucid dreaming is basically dreaming while being aware that you are dreaming.If you are in a lucid dream, you will usually have some power over your dream - anything from being able to fly or making an object or room appear behind a door or inside a pocket right up to being able to change into animals and create a whole world! Lucid dreams have been scientifically proved to exist.
Last night I wanted to fly, and I flew. And I was in total control of it.
Being able to control your dreams, a subject brought up a lot in the movie "Waking Life", an artistic look into dreaming and death.
They say you can tell if you are dreaming by flicking a lightswitch. If you are dreaming, the light will never turn off. In lucid dreaming you can fly about, cause havoc or fornicate with all that you please.