A nice review from Glenn Fleishman on Macworld that looks at an interesting backup/sync option called SpiderOak. He concludes:
If you’re looking for the highest level of privacy and a service that has all of the pieces in one place for backup, sync, and read-only folder sharing, SpiderOak offers the strongest solution.
I’ve known about SpiderOak for a long time now, at it seems right up my alley, but honestly the UI is confusing and ugly. I tried to use it a month ago and just couldn’t find the time to want to set it up. That’s why Dropbox and Time Machine are so powerful — just flip a switch and forget about it.
Still, I’ve heard from many that SpiderOak is a much more secure option — and with iCloud it might make a nice complimentary service over Dropbox. I’ll give it another go.