for all/most cars, the front is negative camber, and the back is positive camber. or maybe it's the other way around but this is built this way so your turns could be more precised. SO! when the front tires wearing out in the outside, it will be switched from front to the back wheels. then the back tires will go to the from BUT the 'right rear' tires will go to the 'left front' and the 'left rear' will go to the 'right front'. this is how they rotate the tires.
i got my tires from Hibdon Tires Plus(not sure if you guys have those place in your area) but if you have their tires, they will rotate and balance for free, lifetime guarantee.
but i guess most of you guys know how to rotate, some don't but hey, just letting you know =)