I use Dropbox as well, John. Copies of my songs are there so I can listen from anywhere. I use Google Docs for sharing. I like the security of it where you have to specifically email an invitation to people.

The external drive is great if you need 2tb of storage. If you are only backing up docs and such..... just a matter of each person's application and what they want to back up. Varying degrees of familiarity will end up with varying methids.