http://ironbark.bendigo.latrobe.edu....eck_guide.html
It's really dumb; it is a tool to get the programmer to think through the program. But wouldn't they have already done that when they wrote it? I think it's pretty pointless to write stuff out with pen and paper, and really it's inaccurate because any misconception you have about the language (syntactically or otherwise) will translate into your pen and paper results...