Today I rode the subway to work so I had the opportunity to try some subway sketches. It's a pretty amazing exercise as you have to draw the person super quickly unless they happen to be sleeping (as LJ suggested). I enjoyed making the drawings but the entire time I was convinced that everyone was aware that I was drawing them. This made me somewhat paranoid so it was difficult to concentrate on the sketch. The entire time I felt like I was violating the unspoken social contract that you enter into once you step on the subway.
I also like some of the doodles on the top of the page on the left. The weird horned dude is pretty cool. I've never been good at inventing weird creatures but this one seems pretty good.