I once had an acquaintance who was into this. He was planning on embedding small magnets into his fingertips, so he could feel magnetic fields. So far as I am aware, he changed his mind, because it would make working with electronics basically impossible. Also, here is a beautiful webcomic that deals with transhumanism.
I remember reading an article about having magnets in your fingertips to feel magnetic fields, that's what I thought this article was going to be about. That is FAR more interesting to me that having a glowing LED ring on your hand. Implants that broaden our senses to experience the universe in new ways would be very interesting, I would like to read more about that. I find cochlear implants and brain-computer interfaces fascinating too. Being able to help deaf or paralyzed people would be a truly great advancement.
The Dark Science storyline probably has the most right now, but the Hob storyline is also significant.
Oh yeah, no, it's about a lot more than that. But I do think it's fair to say that it does a little bit more than touch on transhumanism when (spoiler) ɐu ᴉɯdoɹʇɐuʇ dloʇ doᴉuʇ ᴉs ʇɥɐʇ ʇɥǝ dɹoʇɐƃouᴉsʇ nupǝɹƃoǝs ɔouʌǝɹsᴉou ʇo ɐ ɟnllʎ ɯǝɔɥɐuᴉzǝp qopʎ˙