Scartol: Things I usually include in my first lesson:
... and along the way I toss in the things I find most intriguing; the respect players show each other, the history of the game, how to hold a stone, Japanese terms, etc. I think it's important -- whatever is being taught -- to combine information with excitement.
adamzero: Scartol, I do basically the same thing as you do. Except I leave out Ko until it comes up in the game. To do corners vs. sides vs. center I take three groups of six stones, surround maximum territory in each region (9, 4, 2, respectively), so they can see the difference, and then play both black and white of the first 10 moves of a typical game on a big board, w/out further explaining, just so they get the idea of what looks reasonable. And then we play 9x9. I always play real go from the start, never capture go. I keep people on 9x9 for a while before moving to 13x13, but the move quickly to 19x19. Hane-and-connect should be a no-brainer first, I feel. I never analyze during those initial games, except to say things like "Now which part of the board do you think has the biggest potential" or "How much territory do you think plays on the first line lay claim to?" or "I'm trying to get into your house here-- what are you going to do to stop me?" or to compliment on a good move. I start with a six stone handicap on the 9x9, and someone people win the first game and kill all my stones, and others I kill every stone they've played, but the improvement is always very quick regardless. One peice of advice I can't seem to stress to beginners enough is to keep their stones connected when I threaten to disconnect them.
I've taught probably forty or fifty people this way, at the UChicago Go Club. I'd say that there is about a thirty or fourty percent retention rate, of players who are still there are month layer, but I think this is most strongly correlated to initial desire to learn on that first day. Some people would say this is overexplaining, but the kids here are smart, and its hard to get the feel of a new game when you don't have even the most rudimentary idea of how to realize the objective of the game.