A standard drink, officially, is 10g of alcohol, regardless of form.
Here are the various beer sizes you are likely to encounter in Victoria and, assuming 4.9% alcohol/volume (standard full-strength beer), the number of standard drinks in each:
Glass: 200ml, 0.774 standard drinks - Rarely seen these days, except maybe in the hand of a 102 year old woman at the local RSL.
Pot: 285ml, 1.103 standard drinks - The most common size in Victorian pubs, most literature quotes the pot as "one standard drink", close enough considering how inexact drink counting is in determining BAC.
"Import" size stubby: 330ml, 1.277 standard drinks - A lot of locally brewed beers are starting to appear in this size, ostensibly to make them more like trendy Euro beers, but really because they can charge the same for slightly less beer. Basically an 11oz bottle.
Can or stubby: 375ml, 1.452 standard drinks - The most common size for packaged beer in Victoria, usually quoted as approximately 1.5 standard drinks. Odd that they estimate up for packaged beer and down for tap beer.
US Pint: 473ml, 1.831 standard drinks - Be on the look-out for this one, another 'trendy' size that's just a way to give you less beer.
Schooner: 485ml, 1.877 standard drinks - Relatively rare, but some pubs offer this instead of the pint as a larger size, or as an intermediate between the pot and the (British) pint.
British Pint: 568ml, 2.199 standard drinks - The true way to drink beer. A lot of my mates may be pommie bastards, but they know how to put away the lager.
Longneck: 750ml, 2.903 standard drinks - The equivalent of two stubbies. You should pour your beer into a glass from these, unless you want to look like an uncouth bastard.
Jug: 1140ml, 4.413 standard drinks - The more social(ist) way to buy a round of beers. Problems can arise from the fact that the jug holds roughly four and a half pots worth, which leaves you with the modern etiquette dilemma of whether to use the last half a pot to top up everyone's drink, or if the first person to finish their pot should just have it.
Mini Keg: 5000ml, 19.355 standard drinks - These are usually an outrageous rip-off when compared to the price of buying the same beer in bottles or cans, but they are undeniably a very appealing novelty.
Keg: 50000ml, 193.55 standard drinks - What is connected to the other end of the beer tap in the pub. It is relatively rare for Aussies to have these at their private parties, unlike in America (n.b. an American keg is closer to 60 litres), but the practice is becoming more common, especially with micro-breweries like Mountain Goat in Richmond offering kegs. Part of the issue with kegs, of course, is that you have to buy or hire extra equipment to actually get the beer out of them.
There are other sizes, of course, including the "pony" which is even smaller than the glass, but they are rarely, if ever, seen. The pony, in particular, is a queer artifact of the days before light beer, when the only way to prevent yourself getting too drunk was to drink less.