This is exciting for me. I am a synesthetic...Synesthesia is a "disorder" in which people experience letters and numbers in colors. Other synesthetes experience music notes in color. There' s a wide range.
I personally experience letters, numbers, and emotions/energy in color. For instance, my name c-a-t-h-e-r-i-n-e translates to light blue-red-grey/white-orange-yellow-blue-white-brown-yellow. The colors don't change, they've always been the same. I keep meaning to draw them out but never get around to it.
Anyway, while browsing through my bloglines today, I saw that Gabriel Craig from Conceptual Metalsmithing posted about this. He had seen a video on TED talks about it by Dr. Vilayanur Ramachandran, which is incredible. TED talks is a conference held once a year by a group of people who are at the top of their field, presenting different topics from art to science and everywhere in between. Each presentation is about 18 minutes long. Please have a look...he presents three different topics, and the last one is Synesthesia, but they are all equally interesting. The video is about 20 minutes long.