Blindfolded chess?

I'm a beginning chess player.  I was reading on a forum where someone asked how to improve their play at blindfolded chess.  What is that exactly?  Thanks!

Playing chess without seeing the board

How does that work exactly -  do you just call out moves you would make?  That sounds quite difficult.  Does anyone have experience with it?

It gets easier the better you get, I wouldn't be surprised if pretty much every candidate master and better could play it versus atleast one or two fellas at the same time.

Then there are some blindfold freaks that could do it versus a number of opponents that are just staggering.

A little more about this exists on the recent article posted by Jeremy Silman if you missed it.

http://www.chess.com/article/view/playing-multiple-openings-and-the-fried-liver-attack

Well, it seems that once you get better at chess it more or less automatically follows. I tried it a while back for the first time and it was not that difficult to my suprise. You just call out the moves and so does your opponent (who may or may not see the board).