Googledocs and Zoho (My Adventure)

I had a few questions relating to the document sharing applications:

1. Will you always want to share a document? I don't know about you, but my first draft is very much my own affair.
2. How do you control the fate of your files up on the web? Anyone who has lost files due to computer failure knows the importance of backing up. How do you do this now? And I don't mean in another building, possibly another state (did you ever hear about the company that had their files backed up in the second building in the World Trade Center?). And everyone has heard of the Dot.com disaster.
3. What about security? Heard the old joke about how you should never put anything up in an email that you wouldn't want on the front of the Sydney Morning Herald? I should think that Googledocs and Zoho are pretty much the same. I wonder how huge organisations with trade secrets go about these things.