Failswitch is a service that checks your site is online and when it goes offline, redirects to a backup site. Failswitch will make daily backups of your entire site and reroute your site when needed.
Failswitch monitors your web site 24/7, 365 days per year, from multiple locations around the globe. The site partners with professional DNS service, DNS Made Easy.
The service charges $15 per month or 150 a year billed yearly. Check out Failswitch HERE