Buy a police scanner. You can also spray your license plate with a special chemical that blurs the plate in pictures (this one may not work anymore though).
I wouldn't worry abouit the speed cameras everyone ive passed speeding still has the lense cap on, i think its more of a deterrant than an actuality they dont hace the technology for a system like that YET!!!!
Some areas have automatic speed cameras. I was driving (speeding) with my cousin from czestochowa to krakow and we saw a small flash from the side of the road. I didn't know what it was until he told me that it was a speed camera. He received a ticket in the mail 3 weeks later.