It really depends on what it is you are trying to do. The example is a bit misleading in that it shows a root prompt, this is not required as long as you have rsync and ssh on both ends. As to the CRON job, it all depends on if you want it automatically done or not. I manually run rsync to my web server after I make a change to my local copy of one of my web sites. This cuts back on running rsync when nothing has changed. For info on CRON jobs check out http://codenewbie.com/tutorials/716.html

Hope that helps,
-awl