Tips for doing really quick sketches of people?

[PeggyChung]

hey guys, well i ll try to make this short, im trying to do many quick sketches of people around in my school or in public. so far, its been fustrating, but im willing to work on it. this one (refering to the drawing) was the best i could get and he was just sitting eating his lunch: http://volcano.photobucket.com/albums/v11/ladylioness/qs1.jpg

i should time myself and see the avg time people stay in one pose without figeting too much. thanks in advance :D

[mtw]

Right now my favorite quickest method is describe in The Natural Way to Draw by Kimon Nikolaides. Basically you just scribble out the whole mass of the person while looking at your drawing only sparingly and not lifting your pencil. That takes me about five seconds.

It would be more helpful I showed a drawing like that, but I need to go eat.