> Third, for that Graphviz output, was anything special required? If so, 
> I would toss the code into Tools for others to benefit from.
It's merely the "to_dot" function from Lib/__optimizer__.py (which turns an AST into .dot source code), followed by "dot_to_png" in the same file which invokes /usr/bin/dot on it, which is likely to be readily available on any Linux system.  Would it be reasonable to add "to_dot" to Lib/ast.py? (it's ~25 lines, and very similar to that file's "dump" function.