Quickly navigate your filesystem from the command-line

I have been interested to the topic Data Science for a while. Today, I was looking for any book on this topic and I came across this one Data Science at the Command Line. The book is not published yet and I can read it through Safari Books Online. I then came across the writer's blog. Among many things, I found this page http://jeroenjanssens.com/2013/08/16/quickly-navigate-your-filesystem-from-the-command-line.html very very interesting. Since I found it so useful, I felt mentioning it here. All credit goes to Jereon Janssens.