Well... the thing explained in the movie the secret is not new... its known for a long long time... for the old shamans (like Don Juan Matus) its called intent, and its one of the moving forces in the universe.

The "theory" behind it is that our mind somehow "creates" the reality... if anyone watched the bleep movie, will see that science is at last starting to comprove it. So, if we think a thing will happen, the reality somehow "bends" itself for agreeing with our though, as the thoughts is what create the reality.

The only difficult is that our concentration capacity is SO small... we lose focus in what were thinking several times per minute, and that why we usually dont see people doing awesome things only with the "power of thought". But, if we can keep our minds silent, with only ONE thought in it, for enough time, surely this thing will happen. Remember, the key is to believe. If you believe, if you REALLY believe, than it will happen.