I bought a book a few weeks ago at Borders in Portland called "Facial Expressions - A Visual Reference for Artists". Its filled with men and women's facial expressions. Models from 18 - 90 are asked to expess all sorts of emotions like furious, or sly, or evil, or surprised, well, you get the idea. I think this guy was concentrating in an exagerrated way. It's a great reference book for drawing the face in a different way than I usually do.
I walked into Boynton McKay with the intention to get a chicken fajita wrap to go but as I made my way to the counter I saw a man sketching. I so wanted to stop and see his drawing and other sketches but I suppose I was embarrassed or didn't want to disturb him. Anyway, it inspired me to start sketching right then and there so I ordered my wrap and sat in one of the booths and sketched the booth opposite from me. Normally Boynton's is packed but since it's late in the season and it was the middle of a beautiful crisp fall afternoon, it was the perfect little sketch spot for me. It was a fast sketch relatively speaking and not at all accurate but I loved doing it.