Australian flag.

* Their Southern Cross is more astronomically accurate (it includes Epsilon Crucis) our one omits it

* They have an additional seven pointed star to represent the six territories/states of Australia, the seventh point being added when they took control of Papua to represent anything else they added to the federation as time went on

* Their stars are white, ours are red

But fully agree, I loved that it the Union Jack was replaced with the Aborigine flag at Sam Neill's behest, because after all, it _is_ the future right?