Re: Extending Ki.
Here's my two cents on everything I know about ki.
From observation + minor experience, Ki is not one thing per se. It seems to have a heat element (hot palms) and an electrical element (I have seen a hand full of people who can touch you and shock the begeezes out of you). It appears that it has something to do with the body's nervous system (neurotransmitters) and muscles and endocrine system (hormones).
I've experienced a little bit of the healing when my wrist was tweaked pretty bad before from repeated sankyo. It felt a bit like my joints were wrapped in heat.
The only real demonstrations I've seen were 1. my wrist being "healed" (it stopped hurting and felt better) 2. tai chi master shocking someone 3. sokumen irimi nage, lit. energy throw, being done with NO physical contact
the blindfolded things are pretty cool, but blind people can do stuff like that. I've heard that when you reach a certian level of experience with blindfolded practice you get to the point where you can feel the body heat from another individual and/or feel the aircurrents they make when they move.
what it actually is or how you use it is anyones guess at the moment, but it seems to have something to do with human anatomy/physiology.