I’m much happier now.
If you also ordered your iPhone from Optus over the phone, don’t believe them when they say it can’t be activated outside of business hours. They were only talking about the SIM card and the phone account attached to it.
The iPhone itself, after inserting the otherwise useless unactivated SIM and hooking up to iTunes, works fine. Wifi works, downloading applications works, syncing works, and all is well with the world. Awesome, awesome box of tricks.