Taking unlocked iPhone 4 to Canada? I am visiting Canada (Vancouver, BC) this coming week from the UK and have an unlocked iPhone 4 (bought SIM-free from Apple). 

What are the best options for buying a pre-paid SIM that will give me some data (around 500Mb) whilst I'm away?

I already had a SIM cutting tool to make micro-SIM cards from standard SIM cards.

Jack
Vancouver is the home territory of Telus, so they're probably your best bet. All three of our major carriers (Rogers, Telus and Bell) support GSM and carry the iPhone 4, so you should be fine.

The only Telus pre-paid data plan in BC appears to be $20 for 250MB, http://www.telusmobility.com/en/BC/prepaid/rates.shtml

Rogers has a $45/month pre-paid, includes 500MB, that looks decent, http://www.rogers.com/web/content/wireless-products/plans