Ahem

The Australian government has a National Public Toilet Map website:
http://www.toiletmap.gov.au/

They even have a made a version that's compatible with your mobile phone: http://m.toiletmap.gov.au/

It helps you find a public toilet based on a specific area or along your route to a particular destination.

Ahh this is highly entertaining...
No more urgent stops at a random petrol station =p