@Doug: have you tried our (free) product: http://ncryptedcloud.com? We currently work with Dropbox and will eventually with Google Drive & SkyDrive. Our product works with Windows, Mac OSX, iOS & Android. We also have the Cloud Web Portal which allows you to see your secure file via web. Keys are generated client-side. We use open standard. We don't have access to your data AND you can securely share your files with other people (nCryptedCloud user or not!).

I've written about the problem of cloud security and cloud privacy here: http://vuongnguyen.com/personal-business-cloud-security.html.

We're just a startup who was trying to solve our own problem with the cloud security & privacy. Would love to hear from you.

-V.