As far as I know there are only two stateside places they are illegal, Virginia
and District of Columbia, unless the laws have changed they are legal everywhere else.
Virginia has a very easily spotted sign upon entering the state that they are illegal, and they search for them with electronic devices. Valentine detectors, in my opinion are unbeatable, except when there are aircraft overhead, or the instant on switch is being used. I use mine for entertainment, and still keep the speed down to no more than 10 over the posted speed. In the past year I have been hit with the instant on, being the lead vehicle, and have been right where they are not interested in stopping. Heavy rain
will, in most instances, render radar inoperable. But then speeding during heavy rain will put you in the ditch or worse.
[ July 16, 2001: Message edited by: The Ripster ]