audioguru-yep it's a cheap toy for children, but it's also one of the 3 main components in real polygraph machines. Though I do realize this is quite a bit less accurate then even the worst of professional equipment. This is a fun project-not something I plan to use professionally.
sceadwin-well it depends on what you mean by works. From what I remember polygraphs are reported to be 85% accurate. Yes, they can be wrong and yes you can be trained to fool them but the vast majority of cases they prove to be accurate. Plus again, this is for fun, not something I plan to do interrogations with.