If you can't wait until iPhone 3.0 gets its official release, Whirlpool's collected the files you need to make MMS work on an Australian iPhone.
One of the most-hyped features of the 3.0 version of the iPhone's basic software is proper support for MMS, making it easier to send those neat photos you've been snapping. However, even if you've snagged a copy of iPhone 3.0 via the developer program (or through unofficial channels) getting MMS to work requires carrier-specific files. Enthusiasts at Whirlpool have gathered together carrier files for all the Australian iPhone carriers, making it possible (albeit fiddly) to get MMS and other features (such as tethering) operational.
iPhone 3.0 is due to officially appear mid-year, so if you haven't already gone to the trouble of getting the developer version, all the futzing around may not be worth the trouble. This development does suggest that (contra your cynical editor) we should probably see MMS on the Australian iPhones soon after release. On the other hand, some work is still needed: our tipster pointed out that MMS messages don't get streamed with other SMS messages from the same contact. Thanks Jennifer!