If it were jailbroken and unlocked would that cancel the contract with Rogers?
Is there anyway to cancel the contract by unlocking it or something? I don't want it to be with Rogers, I want to use it in another country. Could I just leave the country and ignore the contract and it's fees?
Yes. It is possible to jailbreak and unlock an iPhone 3GS. You can get the jailbreaking guide for an iPhone 3GS from Absinthejailbreak.com To unlock your iPhone 3GS you can visit TheUnlockSpot.com and get the remote unlocking service. This method of unlocking is safe, simple, affordable, quick and permanent. It doesn't require a jailbreak too. Good luck mate.
Jailbreaking and unlocking wont cancel the contract. You can continue to use the same network even after unlocking or you can use any other network too.
If you want to cancel a contract legally, you need to pay the contract cancellation fees which would be too costly. So. Yes you can just leave the country by ignoring the contract and it's fees.