To ensure I have a good off-site synch of my data i now use DeltaCopy http://www.aboutmyip.com/AboutMyXApp/DeltaCopy.jsp its basically a version of rsync for windows. Its quite simple to setup and works well. The package includes the client and the server.
In my case i have two servers, one local, one remote, the two sync with each other to make copies of each others data on the other server. Then I take a local backup of one of the servers to USB hard disk. So i have an on-line backup locally on RAID 1, that is synched onto another server with RAID 1, this is also then periodically saved onto a USB hard disk. So I would need 5 disks to die simultanously to lose any data.