FYI. Crashplan is pretty cheap and purports to have client-side encryption. They are closed source but they are setup to have you provide a key in the backup client.
I LOVE Tarsnap and use it for offsite backups for my most critical information (configuration, projects, documents, etc). For various reasons it's one of the only systems whose cryptography I trust enough to store very personal information. I think this ends up costing me about 30 cents per month.
However, for things like photos the cost (as little as Colin charges) start to really add up. I do my photos on Apple and recently dumped my library into iCloud (offsite backup I guess) and then I periodically rsync that to my NAS. Photos are also backed up to Time Machine on a separate disk. I figure this gives me a fair bit of redundancy and covers me if iCloud deletes all my photos too.
I've tried to do the Time Machine disk shuffling (swapping disks between home and office) but if it's not automated, it doesn't happen.