VirginBlue have released a range of domestic flight specials. Fares from $49, flights between: 05 Aug 08 - 18 Sep 08 and 14 Oct 08 - 11 Dec 08.
Whilst not the absolute cheapest fares you'll find anywhere, Virgin do flight a bunch of routes that the other discount carriers don't.
Fare summary:
Albury - Sydney $79 AUD
Adelaide - Brisbane $99* AUD
Adelaide - Canberra $89* AUD
Adelaide - Hobart $89* AUD
Adelaide - Melbourne $65* AUD
Adelaide - Sydney $99* AUD
Brisbane - Canberra $99* AUD
Brisbane - Cairns $95 AUD
Brisbane - Hamilton Island $85 AUD
Brisbane - Melbourne $109 AUD
Brisbane - Mackay $69 AUD
Brisbane - Newcastle $49* AUD
Brisbane - Perth $229* AUD
Brisbane - Whitsunday Coast $69 AUD
Brisbane - Rockhampton $59 AUD
Brisbane - Sydney $75 AUD
Brisbane - Townsville $105 AUD
Ballina Byron - Sydney $55 AUD
Canberra - Melbourne $75 AUD
Canberra - Gold Coast $79* AUD
Canberra - Sydney $79 AUD
Coffs Coast - Melbourne $149* AUD
Coffs Coast - Sydney $69 AUD
Hobart - Melbourne $55* AUD
Hobart - Sydney $69* AUD
Launceston - Melbourne $49 AUD
Launceston - Sydney $69* AUD
Sunshine Coast - Sydney $75 AUD
Melbourne - Newcastle $59* AUD
Melbourne - Gold Coast $79* AUD
Melbourne - Perth $179* AUD
Melbourne - Sydney $89 AUD
Newcastle - Gold Coast $55 AUD
Gold Coast - Sydney $55 AUD
Perth - Sydney $189* AUD
Port Macquarie - Sydney $79 AUD
Rockhampton - Sydney $89* AUD
Melbourne - Ballina Byron $129 AUD
Adelaide - Sunshine Coast $135 AUD
Port Macquarie - Melbourne $179 AUD
Melbourne - Mackay $139 AUD
Melbourne - Rockhampton $140 AUD
Sydney - Hamilton Island $118 AUD
Melbourne - Hamilton Island $125 AUD
Melbourne - Whitsunday Coast $144 AUD
Melbourne - Townsville $179 AUD
Albury - Gold Coast $125 AUD
Gold Coast - Perth $239 AUD
As per usual, you can find which days have the cheap flights via adioso.com:
http://www.adioso.com/search?q=VirginBlue
Happy hunting!