What is your opinion of radar detectors?

What is your opinion of radar detectors? Are they effective? If you like them then do you have a make/model that you recommend?

Detector Inspector

Please could you re-state the currant law regarding speed camera detectors. I have a unit that detects fixed cameras and a plug in unit that detects radar laser mobile cameras. What is allowed?

What are your views on laser and radar jammers?

I have recently received info on the above subject and on the face of it they appear just the ticket. Do you have any issues with it regarding legality, effectiveness and use on the continent?