If I sat down and actually took the time to do it right, I might be able to come up with something half-decent, but even a half-decent attempt would take me all day. I just don't have the patience for that. The people I draw on the fly always end up looking like Calvin from Calvin and Hobbes. Must be the tremendous amounts of it I read when I was younger and wanted to grow up to be a cartoonist. Either way, unless I spend a really long time on it, my drawing looks horrible, and the "quality" of my chalkboard drawing is a running joke among the classes I teach. Especially because if you ask a Japanese kid to draw a picture for a class, they lose all notion of the concept of time and take absolutely FOREVER on it, but they will produce a very nice drawing for you more often than not. Oh, the amount of class time wasted even when playing picture bingo because the kids were laboring over the little details of each... and every... picure...