The thing I still don't understand is how/why inflation needs to be controlled anyway. Maybe you've already answered this question, but I can't fathom how in Zimbabwe it now costs something like $200,000 dollars to buy a loaf of bread.
What causes such massive increases in price? Is it simply the fact that demand exceeds supply, pushing prices up? In which case, why do we need the RBA? 
Like I said, this question may have already been answered, so if it has, could someone point me in the right direction?
Let's say that bread costs $3. A person earns $100 dollars a week. Their living costs for that week (hypothetically) cost $97, leaving them with only enough for one loaf of bread. Assume that they only need one loaf, and one loaf can be supplied to them. Therefore demand equals supply.
But say this person gets a pay rise, which is what a typical person wants. Their pay is now $106 a week, leaving them with $9 for bread after living expenses. Therefore they can buy 3 loaves of bread, meaning that there is now more demand than there is supply. Purchasing power is strong.
Assuming that everyone gets pay raises much the same as this person, demand with largely exceed supply. Upward pressure is then placed upon the price of bread - the higher the price, the less people are able to or willing to buy it, meaning that demand lessens.
That upward pressure is inflation. It must be controlled to ensure that as more money is circulating in the economy, goods and services are priced to complement them and to keep the purchasing power of money low.
In the example you used of Zimbabwe, keep in mind that 200 000 Zimbabwean (?) units of currency does not equal 200 000 Australian units of currency (dollars). That all has to do with exchange rates.
But I assume Zimbabwe doesn't have a great economy and so inflation isn't controlled over there.
