I decided to prepare myself for the Intro to AI, a free online course offered by Stanford. I found the course website: http://www.stanford.edu/class/cs221/schedule.html and wanted to download all the slides.
It's time to pull all the ppt files from that page.
wget -r -A.ppt http://www.stanford.edu/class/cs221/notes/
This created a tree of empty directories with one of them that had all the ppt files. Time to clean up the empty folders:
find -depth -type d -empty -exec rmdir {} \;Ta-da! Empty folders are gone.
Remember if you are typing a command more than once in succession there is a way to automate it.