I used to have an accountant who, I found out one day, posted his daily back up tape to himself: "If we have a fire or robbery in the night, we can get the syatem disks back from the bank and be up and running the next day, when the post comes".
I pointed out that if he left the tape on my desk each evening, I could just as easily take it home, saving my company around £800 a year!
I tried BT's digital vault, but found it cumbersome, sometimes it wouldn't recognise my password even when I pasted it, seemed to have a lot of downtime and missed files, without being able to list what they were, so I gave it up as a bad job.