"If Centrelink won't get you above the poverty line, try theft"
Like Suave suggested, don't be above some down and dirty (but hopefully legal) ways of supporting yourself. Being a test candidate for the psych or med departments pays well, and can be a good way of getting a bit of cash in hand and a cheap feed or two. Live on ramen noodles, and always seek sources of free food. Graduation ceremonies are usually big enough that you won't be noticed if you put on a suit and slip in to the reception afterwards for an hors d'ourve or two.
Also, read this:
http://www.phdcomics.com
It's just a bit too accurate sometimes.