Python

Graphviz is an open source program for making site map diagrams. It runs on Linux, Windows, and Mac OS X. The sitemap charts can be generated in many formats: png, jpg, gif, svg, ps, Dia (an opensource program similar to Visio), and others. After installing Graphviz and going through this tutorial, type man dot to get more information on what Graphviz can do.

If you have been using the Python shell and would like to save your commands to a file for reference, just type the following:

>>> import readline
>>> readline.write_history_file("my_history.txt")

If you use a Python IDE like SPE, it will automatically save your history in a tab.

I haven't tried it yet, but check out Moveable Python — you can apparently carry it around on a USB thumb drive.