Apple has dropped the prices of unlocked units of the iPhone 3GS and iPhone 4 for Canada.
As shown on Apple.ca, an unlocked 8GB iPhone 4 is now $549 (available in black or white and ships by October 14th), while an 8GB iPhone 3GS is $375 (available now). The iPhone 4 was never available in 8GB of capacity before.
Current factory unlocked iPhone 4 models sell for $659 and $779 for 16GB/32GB units. To buy an unlocked iPhone 3GS for $375 is a steal for traveling.