I think Australia's pretty much the same as America regarding physical contact etiquette. If a stranger kissed another stranger as a greeting, the receiver would be very thrown off, or possible punch the giver if they were a hetero man!

Flirting wise, a few touches here and there is normal.
Formal...handshake and maybe a pat on the shoulder.

EDIT: I was also reading a body language book and I thought something was interesting. They have found that people who were raised/lived in crowded cities have a smaller personal space, meaning that the talking-space between two strangers is much shorter than those who live in sparsely populated areas. For example, some people in the country who live in isolation find it uncomfortable to even give a handshake, because that requires the other person getting into their personal space.

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