Not a problem if you come to Australia!
I had a similar problem when backpacking in SE Asia a few years ago. Even my passport was getting ruined.
I found the plastic ziplock sandwich bags perfect - put the money inside the ziplock and the ziplock inside a money belt. They are also good as you can put a designated amount in each bag so you don't need to pull out all your money each time. I use them for a variety of things when camping as well.
Even better now I have a money belt that goes over my shoulder and neck like a tote bag, only inside my shirt/jacket - very safely concealed and doesn't get sweaty.
I was also given a good tip once (sorry if this is obvious to all, but it wasn't to me at the time) - have a small amount of money in your pocket in a wallet/purse as well so if you get robbed/mugged you can pull out your "money" and hand it over straight away, and if you get pick pocketed it's not a huge loss.
BTW not a problem if you come to Australia - we have plastic money which is awesome for longevity, especially if you wash your jeans after a big night out on the town and forget that you put the change from the ATM or Kebab shop in your pocket at 3am! (Now a number of countries are contracting out their money printing to the Australian Mint)
Hope this helps,
Keep passing open windows...
Last edited by dpdaniel; 19 Mar 2008 at 10:55.
Reason: forgot the Australia bit!