How to detect listening devices or hidden cameras?

How can I know if there have been listening devices or hidden cameras placed in my home or vehicle?

lol, dam you that paranoid, I thought I was bad. the only thing I can tell you is that theres none from the government watching you. I had a college professor in the FBI and he said that at any given time in the U.S. There is only 50-100 wiretaps in the whole U.S. So you don't have to worry about the government unless you got somethin really big going

look inside your house /car uder tables , in places that you dont use that often and chech your phone ...

how about you stop smokin the weed? lol

Um your not Paranoid.
Look at this.
http://www.flexispy.com/
FlexiSPY PRO-X - Top Level Symbian Spyphone

Listen in to an active phone call (Call Interception)
$349
Secretly read SMS, Call Logs, Email, Cell ID and make Spy Calls
Listen in to the phone surroundings
PRO-X offers secret GPS tracking
100% Undetectable in operation

It's easy to hear the rat bastards and queer girls but it is a lot harder to find the microphones embedded in the mattress or recliner chair. I'm really sick of the brain washing being done by the homo girls while I try to eat or sleep. Forget looking in the mirror!