But here's an idea: giving me direct control over my own brain's functions, via bio-feedback.
Reminds me of that story where a mad scientist is working on a brain control project, and all the secret agencies (CIA, KGB, etc.) of the world are pursuing him to steal his technology. As he is finally cornered, the mad scientist injects himself with his prototype, and then, after a few moments of cliffhangers where he just seems to have had a seizure, shouts in defiant victory "it worked! it worked I control my own brain!"
And then all the assembled secret agents go "what, it's something that lets people control their own brains? that's the opposite of what we wanted" and just leave.
LOL. A device that allowed me to control my own brain would be extremely valuable to me.
Reminds me of a story where the antagonist is an evil telepath, and the heroine is having a long, extended conversation with him (it was that kind of story), and she hit him with "Can you not read your own mind?" as a way of exposing his own inconsistency and hypocrisy.