What is your favorite application of Graphviz?
hippee-lee: We had to write an awk script for a class a while ago that used the output from du for a given folder. The output from the script was a dot file with the directory structure and memory used for each node below the given directory argument. Mine was pretty simple but one student figured out how to make each node look like a folder and color coded the nodes based on the amout of space used.