I was recently commenting on a post in /r/WTF, and made mention of my neodymium magnetic implants. The comment garnered a substantial amount of attention, and I had a bunch of people telling me to do an AMA on the subject. Well, OP delivers.
Me and two of my friends (who may share their experiences in a bit) had parylene coated neodymium magnets implanted into our fingertips in October of last year. We are in no way the first to do this, but you all seem interested in knowing more about the procedure, and more specifically, why the hell we would want to do something like this.
My implants have allowed me the ability to "see" magnetic fields. Any device that has alternating current flowing through an inductive load throws off substantial amounts of magnetic energy. I can feel the shape, intensity, and frequency of this field as the magnets in my fingers shake in response.
They have changed my life, and I think they are freaking awesome. So please; AMA.
Why did I have it done:  This is about the best reason.