Im not sure if anyone has posted this here before.
http://www.policespeedcameras.com/
Quite a good read. Tells you all the restrictions as far as cameras after limit changes, at the bottom of hills, how the radar has to be alligned, etc.
I especially like the theory of going to view your photograph and if there is any other car in the pic (as would be the case on the freeway, etc) then they cannot fine you!
Also I have heard that if you get booked by an actual human police officer they have to be wearing their hat when they walk up to the car (otherwise you cannot be booked).
Another one I heard was if you are speed checked (cop travels behind you and uses his speedometer to determine your speed) then they have to produce a tyre guage and all their tyres must measure exaclty 37psi otherwise they cannot book you.
And last one is that if the have a hand held unit they must take two read outs, 3 seconds apart. They have to show you both readouts if you request this. And you can only be booked for the lesser speed. My Father has used this in Sydney and it downgraded him from a 15-30km to a 0-15km fine.