There's
a great little article by Geoff Gilpin here (warning: PDF) talking about the flaw in the continuing beliefs about "creating your own reality", and "manifesting" things through directed consciousness.
The latest twists on this ongoing mythology are the "What the BLEEP do we know?" promoters and that "The Secret" book/show/whatever, but it's hardly a new idea. Deepak Chopra's been pushing the same basic idea (dressed up as "Vedic Wisdom") for twenty years or so, and the Maharishi's Transcendental Meditation sect took off way back in the sixties. And hey, Christianity's got a lot of "ask, and ye shall receive" wishful thinking, too.
Gilpin's main thrust is one of disappointment about where wishful thinking leaves the world. His basic thesis is that if you sit back imagining that your happy thoughts will change the world around you, the people who you disagree with are left unhindered to go about changing the world around you through more mundane means.