Originally Posted by
MSPeconomist
...The bigger problem with airport security was that size and weight limits for carry-on are much stricted in Australia than in most of the rest of the world and I did encounter some trouble that I hadn't anticipated on that issue.
Carry-on limits are generally enforced within Australia.
Note that with Qantas Mainline you can have 2 x 7Kg (15lb) carryon bags; JetStar 10kg and the remainder allow 7Kg (although, except for Tiger, up to 10kg is ordinarily ok).