Instructions for entering and rules are available on the photofocus website, but in summary:
Enter to win chance at a Canon 5D MK III from @ShootProof & Scott Bourne. Please RT. Info at: http://wp.me/pu7xa-675
The rules allow international entry, however outside of the US you are responsible for tax and shipping etc, but for a brand new 5D MkIII that’s still a small price to pay!