Just got myself one of these bad boys
http://misco.co.uk/applications/SearchTools/item-details.asp?EdpNo=241634

So that makes 3TB of storage I now have

Actually the new drive is primarily only going to be used as a backup device, which is just as well as it's not the quietest of drives but then what do you expect from 4 500GB drives in a RAID configuration?
All I need to do now is find some decent backup software, any recommendations for the Mac?