I'm coming down in a couple of weeks to Sydney with the family and so far struggling to find any vouchers onlinefor the tourist attractions, such as zoo, aquarium, museums, etc. Looks like our bagain airfares may turn out to backfire on us!
Best I found are Entertainment book and recent Sun Herald 2for1 for Taronga, but its probably not worth the cost of the book for one trip and I missed the paper for the zoo one. If anyone has these they won't use they would be greatly appreciated.
Otherwise any inside local knowledge, can trade for some Brisbane tips/vouchers!
If you go to any tourist information stand (there is one near the Sydney Town Hall on George St), you can find these tourist brochures for Sydney and at the back are coupons to some of the attractions in Sydney. The discounts may not be sizable but it's better than nothing (approx 20%).
There is also a Viva Sydney card (it's free) with deals for Sydney. Here are the details: http://us.sydney.com/Viva_Sydney_p4020.aspx
Alternatively you could just watch the group deal pages for deals for Sydney. There are always touristy deals here and there.