Sorry to post so late, but I have only just noticed this thread. I have just got back from a long cold winter in the New England area of the USA.
I do a lot of walking in the Blue Mountains, especially in the Kanangra-Boyd NP. I also try to get away to the Snowies as often as I can as well.
My vote for making water safe is "Clearwater" made by Xinix and available from BPL by mail order. It is a chlorine dioxide treatment that is very convenient to use as it is premixed. I have tried the ClO2 tablets in the past, and while they work OK, they seem to taint the water with a slight chemical taste (IMHO anyway). I find that the Clearwater does not do this. I normally decant it from the bottle into a dropper before each trip (plus a bit extra). You mix it at 1:1000. I have never been sick and I have been using it for over two years now, ever since BPL introduced it.
I used to use a Katydyn Hiker filter, but it weighs around 300g. With the Clearwater, my water treatment kit is reduced to around 25g for a normal long-weekend bushwalk.
I concur with all the above posters as to the tyranny of distance that we face down here in Australia. However the biggest problem is from our gear retailers who, for the most part, insist that gear needs to bombproof for Australian conditions. I have no interest in a 4kg backpack that will last for twenty years. I would much rather a 500g model that I will replace in maybe 4-5 years at the most. The advances in lightweight technology are such that whatever I buy today will most probably be superceded in a couple of years. Why would anyone want to lug around any more than they absolutely have to?
Anyway just a few thoughts. I have seen nearly all the Aussies who responded to this thread posting on the various BPL fora over the last few years. Nice to see us all in one list.
Any other lurkers?