I want to add a extra fan to a xbox I am goin to put it in like a pc case or something and I want 2 fans so one can suck out the air and other to suck in. Where would I hook up the fan like is there any spots on the mobo where I can get like 5-12 volts of power? Any ideas or anything thanks.

Um, ya. You can get 12V from the HDD power cord.
Pick up an adapter that will plug into the HDD power plug and feeds the fans.

On 1.0 xboxes, you can put a heatsink in place of the GPU fan and then use the fan controller that the GPU fan plugs into.

M$ spent millions designing airflow in the Xbox and how it relates to the shape of the bottom of the tray and if you add a fan you'll mess the airflow up and your xbox will run hotter.

That may be true for the Xbox, but he's installing it in a PC. Plus, I put an extra fan in my box and there's been no problems. It's been running cooler. I used to set one on top of my HD when I had problems with it.