As a footnote to Aleks' 'Losing Play' piece on monday, here's a great post from a blog named Wonderland, transcribing a GDC keynote speech by videogame theorist, Raph Koster. Definitely worth a read, if only for the bit where he says:

"Here's the thing: ask a gamer about Grand Theft Auto's hooker moment, they see this: pac-man eating a cherry. They've grokked it: it's a power up!"

I'm not sure what 'grokked it' means but I think I agree with him. You can read more about the speech here. Lots of interesting ideas.