I saw three fighter jets over North Canberra yesterday afternoon and was pretty sure they were F-16s. Due to the garish paint jobs I thought they might be USAF Thunderbirds but they were RSAF Black Knights. http://www.airforce.gov.au/Operations/Flying-Operations/?RAAF-hPR1ZyeqIMWKiaNtrjPMdufiX/RBJSoR
Fifteen minutes or so ago I saw three Hercules flying over but they're not mentioned on that flying operations page.
Saw the Hercs as well as I was driving to work, no idea what they were doing, however they lined up on the runway together (according to someone at work anyway) so ids say it would be a training exercise, I would say it was some form of display, however the same three C130s were spotted later on doing the same thing in Melbourne.