Personally I load all RAW photos onto my main linux PC (which uses RAID 1 HDDs). The best photos, once edited and polished, are sync'd to the PVR and Mac (where they then move to the iPads for display). I also run full & incremental backups of the PC, Mac and core PVR files via wifi down to a DNS-323 with RAID 1 hidden in the garage.
Lastly I take an encrypted snapshot every month to work.
PC/HDD crashes - RAID will probably save me. No loss of work.
PC explodes - Garage backup will save me. Loss of (at most) 1 days work.
Burglar - Garage backup will save me. Loss of 1 days work.
House and Garage burn to the ground. Loss of at most 1 months work.
Its all automated (except taking the encrypted snapshot offsite).