I normally backup my WordPress site using the export command and save it to my Dropbox account in case I need it at a later date. However this does not backup plugins and content. Most of my posts I use image hosting as a makeshift CDN to avoid storing them on my server.
I started looking for a method of my own. My search ended when I found wpTimeMachine which makes it simple for me to back up my entire WordPress site to my Dropbox account. It also can perform the task of automatically backing up the MySQL database, themes, plug-ins and all files and images I may have uploaded under my WordPress site. How awesome is that!
If you’re not backing up now… I suggest you do so.