We opened a USD account (happen to be with CIBC, but any Canadian bank will do). When the rates are favourable, you put money in. AND you don't have to pay a bank fee on the exchange when you withdraw! We know we're going back, so why not?

Chris55 - I personally feel it's best to use JAD down there, but USD is the next best thing. You will get a better deal on anything if you pay in JAD usually. The cambio's do give you a pretty rate down there. Having it in hand when you leave is a good idea. Bank computers can cack out, you know? You don't want to spend your vacation at the bank machine .... trust me!