This document discusses data persistence in the cloud. It notes that data models are likely to change over time and advocates a "data first, structure later" approach. It introduces SimpleDB as a schema-less, key-value data store with a RESTful API. It also discusses using content repositories like Apache Jackrabbit or Apache Sling for managing unstructured data, versions, full text search, and other features while providing a persistence manager and APIs. Commercial options are also mentioned.