A few alternative suggestions:

• Use the name of the Account. For example "Gliffy Inc." or "My Personal Account".
• Use the name of the Account with 'documents' appended. For example: Gliffy Inc. documents, or Gliffy Inc. diagrams

I know some of these suggestions might bring up other issues such as how to deal with the whole 'Change Account' thing. Maybe this would be one way to make the 'Change Account' thing less confusing for users? For example, we could list both 'My Account Diagrams' AND 'Gliffy Inc. Diagrams' in a single document manager.