This may sound like a silly thing to have in general, but I can think of at least five or six different examples where a Porn Detection USB Stick would come in handy. The prime two examples being helping someone to quelch an addiction, and in the workplace where possession of porn is a crime. Trying to figure out what sort of weird stuff you roommate looks at so you can blackmail them is probably not the best use.
A lot of people may say that to own porn is within their rights, and while that is true, where you stash your porn can get you into trouble (like on a company laptop). This flash will look into archives, and check headers for image and video data, even in files with obscure file types. This would be very useful for a computer illiterate probation officer or even a company IT manager who needs to check some 20-30 computers. This will cost about $100, and will make sure that no one has anything they shouldn’t have.