I follow The Worst Things for Sale blog. It goes without saying that there are many horrible things for sale, and I'm surprised there's only one blog on the topic (though I'm sure there are more. Perhaps even a Tumblr.)
Sometimes the object in question is.....well, I won't say "good". I'll say.....fascinating? Obliquely delightful? Like the USB polygraph. Now, I am not an officer of the law. Nor am I even a Private Investigator. I'm unlikely to be any of these things, ever (I have a distinct aversion to things like push ups and getting shot at), but can you imagine being out in the field with your laptop, and having a suspect make one of those "You can polygraph me any time you want! I'll take one of your lie detector tests!" and just...throwing down? Like, "Touché, sir, here it is and here you are. Buckle up!"
As The Worst Things for Sale says, though, "Official court opinions (including those of the Supreme Court) have been
issued stating that polygraph results cannot be used as evidence due to
their inaccuracy." This is interesting, because 1. most people know at this point how to "beat" the polygraph (it was discussed in at least one of my college psychology classes, probably more) and 2. a local newspaper article on a murder and the fact that the suspect's girlfriend is "standing by him" has mentioned how she's taken a polygraph.
(again, I am not an officer of the law, but for the defense lawyer to say the dude's girlfriend is an "honest person of integrity", even though she was sleeping with the married man who is suspected of killing his wife who was, incidentally, her friend? Yeah, no. That one will not be a slam dunk for the defense.)
Despite what I know (or think I know) about the polygraph, it hadn't occurred to me to wonder if they were in fact still admissible in court. I am also, however, not a lawyer, so I think I'll just let this one lie. But, if you're interested, there is an American Polygraph Association. Can you imagine what their conferences must be like?