I've seen the stars of the Southern Cross painted, tattooed, on stickers and hand drawn in texta across the persons and vehicles of any number of nationalistic young people in recent years. Personally I think these kinds of displays of nationalism - while often made by perfectly decent people - are a little American - over the top and tinged with a kind of intolerant tribalism.
Saying that everyone who feels proud of this country is an ignorant bogan or redneck is to oversimplify things - there is a lot to still celebrate about Australia (something that the joyless, overcritical wowsers on both sides of politics forget sometimes). The things that I like most about Oz is the laid back but practical nature of how we do things. The whole quiet achiever thing. This strikes me as the greatest sign of confidence - not needing to jump up and down and wave your arms around.
The rise of the Southern Cross as a sign of national pride is extra puzzling because it's a constellation that can be seen from most places in the Southern Hemisphere. Four other countries like it so much that they have it on their flags. You could argue pretty easily that the Federation star, with its 7 points representing the states and territories is a more distinctive symbol of national pride. (Let's overlook our colonial master's flag still perched up in the top corner - even the Barmy Army has been heard to say "get your shit stars off our flag")
The Eureka flag - which has been adopted by a range of groups from trade unions to white supremacists - could also be ripe for reclamation. Of course, it would be better if it was accomplished by some kind of meaning popular movement against unfair oppression - but like that's going to happen.
I've got nothing against the Southern Cross itself - it's a good looking group of stars and handily can be used to find south without a compass - but it's not uniquely Australian.
Australia
Brazil
Brazil actually wins in the story about why the Southern Cross is on their flag. It represents the stars they saw on the morning of the 15th of November, 1889, the day the Republic of Brazil was declared. Each star on the flag represents one Brazilian state. On top of this,
the flag portrays them as they would be seen by an imaginary observer an infinite distance above Rio standing outside the firmament in which the stars are considered to be placed.(flagspot.net)
New Zealand
Papua New Guinea
Samoa
(images from Wikipedia and in the public domain)