Visualization?

There's a theory I learned about in Psychology that many people swear by (Schwartzenegger, for example.) It basically says that your subconscious doesn't have a 'language,' but can get visual queues from your conscious mind. So if your subconscious is controlling your autonomous functions, telling your body there's a famine since you're constantly taking in less calories than you need while dieting, then your body will store fat rather than letting it go. If, however, you take a few minutes every day to imagine how your body should look, seeing it without the fat, basically reassuring your subconscious, then it will instruct your body to let go and work with you, rather than against you. This is supposed to help well with bodybuilding and shaping, imagining the body you want, and your body will help you get there. Very intriguing theory, basically communicating with your subconscious to make sure you're on the same page, and creating a mental shield against the evolutionary instincts your body holds to store fat for the hard times.

Has anybody tried this and had any success? I'm constantly trying to visualize what I would look like thinner, but I can't imagine it since I've always been overweight, even as a small child. It would be nice to be able to tell my body 'where' to lose the fat (not the boobs, please and thank you) and where I'd like to build muscle (sexy quads? tighter butt? Seriously, if you've tried this successfully, what's your technique? I really do believe the mind is a powerful thing if used correctly.