If you're in WA sign up at the fuel watch web site and vote with your feet. They send you emails everyday telling you where the next days cheapest fuel is in the areas you select.
There's often a 15/16 cents litre price difference between one servo and another around the corner. BP are the biggest offenders by far for price gouging. I refuse to use them out of principal.
http://www.fuelwatch.wa.gov.au/
