Rep Power: 717

Check this out,
I don't know how much weight it would carry here in Ontario, but as the article says, it just may put enough doubt to change a ticket

http://www.cnn.com/2007/TECH/10/26/ticket.gps.ap/index.html

 
Rep Power: 680

thats actually crazy... i dno if it would work here tho

 
Rep Power: 777

wont work because the speed it tracks you going is obviously not as accurate as a radar detector.. too much doubt

 
Rep Power: 684

good point

 
Rep Power: 717

All it really needs to do is put doubt that there may have been an inconsistency with the Radar gun. If you can prove that there is an inconsistency in the radar gun, or that it may not have been properly calibrated then you should be able to use it, as our law states "Innocent until proven Guilty" and if you cannot prove without a doubt that the speed stated is the speed actually traveled then by law it is in your favor.