Adorama, B&H, Amazon, J&R... lots of good reputable retailers out there. Beware of extremely low prices from seemingly professional websites. These scams pop up all the time. Frequently, Googling their "official" address will take you to a giant field near West Palm Beach. I would stick to the trusted few listed on CanonRumors price watch. Otherwise, you'll probably end up with a complaint in to the police with no hope of ever getting your money back.