Simplicity matters, that's why a picture is worth a thousand words.
Here are some tools written in Python or just open source, that will help to make your ideas and architecture accessible to the rest of the world.
Asciiflow - online editor for Ascii diagrams (Java, GWT + GAE, BSD)
blockdiag - diagram images enerator by Takeshi Komiya (Python, Apache 2.0)
You can also draw ASCII diagrams by hand using Far Manager (Windows, BSD):
- Shift-F4, open or create new file
- F11, call plugin menu
- D, use Draw lines plugin
- Shift-Arrows to draw lines and boxes
- F1, if you're lost