Australia is a massive country that consists primarily of sand, rocks and poisonous animals. The vast majority of the country is difficult to access, and as a result, the majority of local geohashers are based in capital cities - which are usually on the coast. This causes quite a few problems, as every capital city (with the exception of Canberra) has a significant percentage of water that's unexplorable.
You can obtain a list of Australian geohashing groups in the Australia category. Canberra's is obviously the coldest, followed closely by the regions of the Antarctic that are administered by Australia.
The majority of Melbourne's urban area is evenly divided between two graticules, -37, 144 and -37, 145, with the CBD and inner suburbs lying in the west graticule.
It is so much cooler (as in temperature, and as in awesomeness) than Sydney could ever hope (or want) to be. It is also cooler (as in great; fine; excellent; socially adept) than Canberra, though so is nearly everything (except maybe Adelaide). Plus Melbourne has good coffee.
Melbourne is stocked full of good looking, talented and of course modest geohashers. It's currently the most active Australian City, comprehensively thrashing its nearby and less fortunate neighbours in South Australia. Frequent hashers are:
The Victoria, Australia page has a map of which graticules have been deflowered so far.
Located on the split of (-34,138) and (-35,138), Adelaide is the capital of South Australia. Due to the splits, the graticules also contain a number of surrounding towns on the both north and south of the city. Roughly 50% of the combined graticules is land, with the graticule used for meet ups will be the one closest to the CBD where possible.
Sydney is Australia's largest and oldest city, and is full of interesting places and twisted, hard-to-find streets. It is a rich cultural tapestry with hidden surprises lurking around every corner, waiting to be found.
In other words, it's perfect for geohashing but suffers somewhat, namely because half the graticule is way out in the middle of the ocean. That doesn't stop Gormster and RikkyC who make an effort to get out and about to fly the flag for the New South Welshmen.
Brisbane (the city) is split into two graticules by a longitude line just west of the city centre. The eastern graticule at -27,153 is called Brisbane. The western graticule is inland at -27,152 and called Ipswich.
The Brisbane graticule contains the city center and densest population areas of Brisbane. However the graticule is also approximately 75% ocean, and 5% islands that are not easily accessible (especially on short notice). This leaves the graticule with only 20% viable area on short notice. The Ipswich graticule contains the outer suburbs west of Brisbane, as well as Ipswich, Mount Glorious, and alot of empty space on the way (but not quite all the way) to Toowoomba.
In terms of geohashing, Brisbane is kind of like a subterranean (or should that be subaquatic?) pacific ocean volcano; simmering away with potential but yet to burst through with an explosion of activity.
The region consists of farmland, National Parks, a generally dry lake, and a few hills that are locally called 'mountains'. Also to be found are dirt tracks, ravines, cliffs and at least one mountain worthy of the name. Canberra (the largest city found in the locality) is more commonly known as the Politics, Porno and
Pyro hub of the nation, but sometimes also referred to as Our Nation's Capital. We love our city. We especially love the porno(graphy), pyro(technics) and pro(stitute)s. Canberra is renowned for being a navigational nightmare due to its high number of roundabouts.
Canberra started out with a hiss and a roar back in the early days of geohashing, but appears to have atrophied somewhat. It's probably something to do with politics.
 Perth & Western Australia
Covering a third of the country and with very little population, this state is every virgin-seeking geohasher's dream. Make sure to pack water, fuel and a satellite phone. If you're the kind of person that prefers to stay within 200km of other human beings, Perth and the south-west is probably more your style. Perth city is split over 4 graticules, although the western two are slightly waterlogged.
 Awards and stuff
Australia's an awesome place to go and find virgin graticules, if you're prepared to hire a helicopter and / or rescue party before you head out. Take a look at -31, 140 (Bengarie, Australia) - a long, slow and relatively painful death awaits the geohasher who sets out to find a hashpoint on foot, bike, car, or anything aside from a sizable 4WD with a metre's ground clearance and four days worth of supplies.
- No Public Access - With a lot of the inland graticules falling over farmland, it's nigh on impossible to find a hash which isn't on some farmer's property way out in the back blocks somewhere. Whilst walking onto a field isn't necessarily going to end with a firearm discharging and air ambulance trip, it's considered quite rude to trespass onto someone's private property. Wherever possible, Australian hashers try to find the property owner to get permission to hash on their property. This proves difficult in many cases, because the farmyard can be some kilometres away from the field in which the hashpoint falls.
- Velociraptors are the least of our worries - There are literally hundreds of poisonous animals living in forests, next to waterways and under people's houses, it's hazardous to do cross-country trips through bush or scrubland unless thoroughly prepared. Remember: Steve Irwin was thoroughly prepared, and he still fell afoul of an animal.
- Mother Nature Most of the coastal hashpoints are relatively mild-weathered, but inland hashpoints are often in tough areas where there's no water, and the ambient temperature in the 40 - 50 degree celsius range. Many a tourist or townie has met their end through assuming it's OK to push on through the next stand of impenetratable undergrowth only to forget which way they came in, get lost, dehydrate, and die.
- Opportunity doth knock We're hanging out for someone
stupidcommitted and enthusiastic enough to go hashing somewhere in Alice or the central desert somewhere, because they won't have the slightest problem getting the 'hot' geohash award.
- Gooooo sppeeeeddddd rraaacceeeerrrrrr Potentially, (if the Germans don't beat us to it by getting a hash on the Nürburgring) and someone's in the right place at the right time, we could also achieve the fastest speed racer achievement. The roads in certain parts of outback Australia are speed-limit free; if someone's prepared to drive the 23 1/2 hours to get to a hash in the middle of nowhere at 180 kmph, that would be...awesome.
- Public Transport & Personal Motive Power Many Australian hashers try to get to their locations using bicycles or public transport, but the country lacks the infrastructure and public support for this to be a valid option in every single hash.