I’m in the process of re-vamping my workflow to accommodate the switch from Aperture to Lightroom 4, and in the process was thinking about my data backups. I use BackBlaze to handle my cloud backups, and I have been very happy with them. I also have a NAS that uses RAID 1 (mirroring) to keep data safe at my house. I also use Time Machine to keep my home Mac’s backed up locally as well. All of these backups cost very little (backblaze is dirt cheap) but just add to my piece of mind. Now I just need to get myself as comfortable with LightRoom as I have been with Aperture and I will be set.