In the VietNam war, the term had two meanings. It could be used to refer to an infantryman's rifle, or to the yoke used by the Vietnamese to carry buckets or baskets (see http://www.ov-1.com/misc/lingo.html).
Some people also use "idiot stick" to refer to the very old style of semaphore turn signals used on VW beetles in the early years (see http://www.ctel.net/~drotski/beetline.html).
Steve Dean wrote an SF short story titled "The Idiot Stick", and Damon Knight did one titled "Idiot Stick". As I haven't read either one, though, I don't know which meaning they were using.
Finally, "idiot stick" has also been used to refer to the old comic slapstick from vaudeville days: "Like slapstick comedians straight out of vaudeville, the National Gambling Impact Study Commission members hit themselves with an idiot stick Monday when they voted to recommend banning college sports betting in America. " (That's from http://www.lvrj.com/lvrj_home/1999/May-19-Wed-1999/news/11203793.html).
All, in all, a remarkably flexible pair of words.