I love asciiflow.com for creating these sort of pictures. I'm a firm believer that the closer your documentation is to your code the better maintained it will be.

Not too long ago I had a project that was implemented as a complex state machine where the requirements kept changing, and keeping the documentation as an ASCII diagram in the source code had a couple of benefits: * It meant that the documentation could be updated when the code had to be changed * I didn't have to hunt for the diagrams on the project wiki when I made these changes. * The diagram was kept in version control with the rest of the code. Each commit/branch had a diagram that accurately reflected its state.

I could then use Ditaa to convert the diagram to a more appropriate format when updating the project's wiki or emailing the customer

[1] https://web.archive.org/web/20130813045206/http://www.asciif... [2] https://github.com/stathissideris/ditaa