Are you talking about actual cloud computing or Google Apps?
Amazon has a well-established cloud computing platform. In terms of security, it is guaranteed to be several notches above anything you can get from another vendor, or assemble at home. They have firewalls and jumphosts so even their own staff can’t access your data.
Understand that cloud computing gains you flexibility, but you lose in the reliability angle. Individual nodes in a cloud can and will go down without warning.
For most individuals, true cloud computing does not make sense. Clouded app offerings are a different beast, though.
