The PhonePad Address Book has a feature that enables you to stored an unlimited number of documents for each Caller (Address Book entry).
Add
Add a new document.
Edit
Edit the selected document.
Delete
Delete the selected document.
Open
Open the selected document.
Save
Save the selected document as an external file.
Documents stored here are only for the selected Caller (Address Book entry). Each Caller has their own set of documents.