Autopilot blogging is actually a blog running on its own using a plugin which automatically post duplicated content from other blog and article directories. I found some people really make money from it but I don't actually encourage anyone to use it.
Auto blogging uses scripts where you can upload massive content in few clicks to be scheduled in the future so your site will be set for a year without you touching it ... or ... you have a program/script that fetches data from some other blog and post it as your own... and you again doing nothing.... It is a nice approach if you actually know what you are doing... but if you are just one of those people who wants to experiment on this using your site that already has a ranking... I suggest you don't. Do your experiment using a unused domain that you can dispose of.... This auto-blogging can work for you or will work against you so I do suggest that you isolate this "project" of yours in another domain... why? duplicate content... that is why.
I also agree with Gator. These 'auto-pilot' blogs may give you a little money, but the results are not that great. Plus, you would have to set up about 100 blogs just to get any results. Basically, you just set up a blog at any free blog site that has "automatic pinging" as a feature. Usually, Wordpress is a popular choice, but I like blogs.se better for the simple fact that it is easier to set up and you don't have to bother with those annoying plugins. Also, you will have to set up a content grabber either via rss feed or with a pipe..better known as a Yahoo pipe. It just grabs articles via your keyword chosen and plaster them on the blog. It does it automatically and everytime it grabs new content, your blog is pinged and you will get visitors even while you sleep. While this seems like a good idea, the terms are short lived. I would suggest using a content grabber and REAL written articles together.
bottom line being: autopilotblogs are pretty close to what people mean when they use the word 'spam'.