A curious new trend in body modification is implanting magnet in a finger. Apparently, this gives the "implantee" a new sense of being able to "feel" electromagnetic fields.
According to Huffman, the magnet works by moving very slightly, or with a noticeable oscillation, in response to EM fields. This stimulates the somatosensory receptors in the fingertip, the same nerves that are responsible for perceiving pressure, temperature and pain. Huffman and other recipients found they could locate electric stovetops and motors, and pick out live electrical cables. Appliance cords in the United States give off a 60-Hz field, a sensation with which Huffman has become intimately familiar. "It is a light, rapid buzz," he says.
http://www.wired.com/news/technology/0,71087-0.html - via Boing Boing