Can Australian Dollars be easily exchanged in Egypt or would it be better to take all the money as US dollars?

Yes it is easy to change Australian dollars in Egypt, I always travel with some US notes on me just in case but I have never had trouble changing OZ dollars there.
Enjoy :)
In Egypt, at least in Cairo, they tend to take anything that smells money, however, I'm not sure about the exchangerate! Some countries takes ANYTHING, to 'help you out' , but if you compare the exchangerates with other currencies ($, euro) it might not be very favourable.
Not sure how it is in Cairo, but you can change them for sure.

Surprise! Egypt is one country that really has good exchange rate for currencies other than US or EURO. The spread between buying and selling currency is also quite small and that is a good thing. So just take your AUD and it will be fine. I made the mistake of changing my money from CAN to US.

Australian Dollar notes can be exchanged at any bank in Egypt very easily.
They started accepting Oz dollars in banks about 6 years when the Egyptian govt floated the Egyptian Pound, which was kept artificially overvalued against other currencies. From memory, used to be fixed at 1$US = 4 EGP, regardless. Enough of the economics lesson...
You will get the full official exchange rate at all banks. This daily rate can be found on the National Bank of Egypt web site: www.nbe.com.eg Select 'English' in the top left hand corner as the whole site is in Arabic, then currency prices at the bottom of the page.
I've even emailed the National Bank of Egypt with questions about currencyand banking policies in Egypt, and, too my surprise, have received speedy replies that have been really open and helpful. Think this is the only time any business or hotel in Egypt has ever replied.
Mmm..I'm starting to sound awfully like an economist which I'm not (my education is actually in History and Psychology)
David