I saw an earlier post from max_london that said they had been to the embassy to get their visa stamped and I must admit I had a huge panick!!!!
We are due to fly on 30th October and was under the impression that I didn't need a physical sticker.... so I have just been through my paperwork and emails and confirmed that if UK passport, travelling from UK to Australia then the Visa is electronically attached to the passport number, so providing you haven't changed your passport since the visa was approved it should be fine.
I have printed copies of the emails etc just in case even though it says you don't need to.
Julia x