One of the best ways to create a passive income online is to start your own blogging business.  You can write about stuff that you find interesting or that others find interesting and are looking for information about.  By providing useful information and promoting other's products on your blog, you can make money.  It does take some long hours and dedication to get it going, but once you have things set up, you can bring in that passive income.  Further information can be found at the link below.