There *is* a Down Syndrome Australia. Is it the organisation you're thinking of (not the Yahoo Group)? I'm pretty sure they don't have a website, but it's basically if an issue comes up that is worth making a statement about (eg, the doctor who was not going to be allowed to stay in Australia because his son had DS - can't remember now if DSA responded to that or not), then the different state associations will get together and agree on what should be said/done. I'm not sure if they have regular meetings or just as needed (think it's the latter). If you wanted to contact them, either chat to your local DSA or maybe contact DSANSW?
Cas