Interest rates in Australia

Recently, I had opened a bank account in Australia.

At first, I was a little pissed by their fees. You have to pay small fees for a lot of things that are completely free in Germany or Japan:

- usage fee for an ATM of your own bank: 1$

- transfering money from your account to another account: 1$

- using your debit card (EC Karte in Germany) at a restaurant or similar: 0.6$

Then, I stopped being pissed... Quite the opposite:
The interest rate for the money on your account is 7%!!!
This is totally unbelievable for me---however, it is true.
I have confirmed that almost all Australian banks pay such an interest rate.

I am not really good at financial things. But, it seems to me that for a risk-free investment, that still keeps your capital flexible (this money can be withdrawn anytime!), this is unbeatable.

I strongly think about putting all my savings onto such an account.
Since a lot of smart people are reading this blog, I would like to ask you for advice:
What could be wrong with this strategy? Please write your answers as a comment (or email me if you prefer privacy).

The only thing that I could think of is the risk that the Australian dollar might fall compared to the Euro (most of my current savings are in Euro). However, 7% per year is still awesome, isn't it?