I have an upcoming polygraph for a clerical position for a municipality. Of course I'm nervous about it, but I sort of question it's weight in the hiring process. I mean, I applied and was selected to go on to the clerical skills test. I passed those and then was selected for a phone interview. That went well enough for a real interview which also went well, and now the polygraph is the last step. Which makes me wonder what they do if the last few (and logically the "best" in all other aspects) candidates fail the polygraph...it also bothers me that the polygraph is a condition of employment but they don't tell you that until you get through all the other steps. I get that it is logistically more convenient to polygraph the smallest number of candidates but if they would advertise it as a condition of employment to begin with they would likely have fewer candidates to sort through in the first place.
As a side note, a friend of mine went through the process and currently works there, and he said he inadvertently "lied" on one of the questions (which didn't raise any flags) and that the one inconsistency they brought to his attention was a question he had definitely told the truth about.