Ah... well in that case, if you're going long enough to stop buying Optus service in Australia for a time, I can see how that would be advantageous. If it's less than a month at a time, a contract could still be a better deal (since the phone should be unlocked at day 1). And of course, if there's a permanent or long-term move in the phone's contractual future, then going pre-paid is a no-brainer.

I'm just commenting to live vicariously through you - I simply can't justify an iPhone until my trusty Nokia 6100 dies... but then, SOLD!