Brad,

What you describe is what I've referred to as Data Spaces in the Clouds (Fourth Platform) for a while :-)

Yes, there is some confusion about the literal interpretation of the phrase: Data Portability (free movement of data across platforms). We don't necessarily want free movement of data across realms (unless we explicity enable it in our space). Instead, I believe we seek Open Access to our Data Spaces with access control granularity.

To conclued, we do need Data Access by Reference facilitated by portable Data Containers (Data Spaces) in the Clouds. Of course, these containers can move themselves, or data from the clouds to other locations, wholesale or via replication and synchronixation. In all cases using standard protocols and existing infrastructure such as the Internet and Web.

Links:

1. OpenLink Data Space Wikipedia Page
2. OpenLink Data Spaces (Open Source Edition) Home Page
3. My Data Space Profile Page
4. EC2 installation Guide
5. How to get a Gateway into your Data Space (i.e a URI for Your Data Space) in 5 minutes or less
6. Recent WWW2008 Presentation about Data Portability and Data Accessibility (PPT)