my home setup: all linux boxes (and VMs) go to a 4TB Netgear NAS over SMB using CrashPlan’s free version (encrypted and incremental. might do a wee piece on that soon).
NAS to external 2TB external USB twice a month (this is drive is stored remotely the rest of the time).
i realise that my data is then only being stored in two locations but another 2TB drive isn’t an option at the moment.
server setup: backed up nightly to Amazon S3 using Jungle Disk. VM snapshots taken a few times a week. files and databases also archived to Dropbox.