It's not quite clear what your goal is in doing this - are you trying to make your site better able to withstand outages? Or just publishing more content? If it's the former, this really only makes sense if you use the same domain name and something like round-robin DNS so that your visitors get directed to whatever site's available. If you're looking to publish more content, perhaps for SEO purposes, the previous poster is correct - search engines don't like this and will likely penalize you for it. It's better to concentrate your effort on one strong site to build up traffic.