I won't name names, but I interviewed and was hired by municipal police department.

be careful answering that as your anominity may be compromised

Gideon,
     Question, who'd you take the polygraph with?  An agency?

First, thanks to everyone who replied with thoughts on whether to take the poly test or tell the examiner I knew countermeasures in hopes of being waived.

Because I really want this job, I decided to go in and take the test.  My worry is that I'm kind of a natural 'screamer' anyway; at the doctor's office, the dentist and certainly hooked up to a polygraph machine.  But I kept my breathing pattern steady and reacted strongly to the control questions just in case.  I found it very helpful to keep a mental image available when asked a relevant question; anything that will calm you while answering.  A child, your spouse, the ocean, whatever.  Just concentrating on a calming mental image can slow your body reactions.

At any rate, the pre-test interview was very straightforward and the test itself was simple.  Maybe ten questions.  A couple of controls like my date of birth, but other than that, a straight list of relevant questions about specific drug use, theft of money, truthfulness on the application and such.  We went through the test twice and I was released.  No post-test questions, only a "you did good," which made my day.

I think what made me so nervous was knowing that a polygraph can catch liars but it can also trip up honest people.  There's a great advantage to knowing calming counter-measures.  After all, it's basically an unsubstantiated interrogation in a stange environment with a trained professional who's examining you for every behavioral and physiological anomlay he can find.  It's hardly an easy 30 minutes.

The test was my third and hopefully my last.  Good luck to everyone esle to has to experience it!