Python Reversi

My first programming coursework. The task was to use Python to develop a multimedia, imaging or game program. For those of us doing games (read "just about everyone"), we were pointed towards Pygame. It's rather ugly, but I haven't had time to design any decent graphics for it, so it's all squares I'm afraid. I might release a version which is more interesting to look at if I don't think of something more interesting to work on. Works fine on OS X and Ubuntu. No reason for it to be anything but fine on Windows, but the text may be a bit off. Constructive criticism welcome, as I'm a novice to this. Just run main.py to launch.