To actually get your brain reduced to a nice cottage cheese like substance watching HULU you'll need this:

www.hotspotshield.com/

This makes it looks like you are in the U.S.
There are some minimal ads, worth it.

Is safe to use? - As far as I know. As in not malicious software you mean?
Does it work in Australia? - Yes.

Short version: Every computer on the internet has an Internet Protocol (IP) address. By checking your IP a site can tell (pretty much) which country you are in, even which city. This is why you get those stupid ads sometimes that say something like "there are 5 available women in Brisbane right now".

Anyway. HULU, due to some [b]American[b] copyright laws, can't "distribute" its content overseas. Using a proxy, like hotspotshield, you connect to the internet through an american IP. You look like you are in the US.

Appendix: You can see your IP (in Windows) by
Clicking Start > Run
Type cmd and click 'open'
command line window will open
type ipconfig and hit enter