Objectify-Appengine is a thin Java wrapper around Google App Engine's low-level datastore API that allows you to persist type-safe POJO objects. It provides a human-friendly query interface, generified key, query, and prepared query classes, GWT-able entity objects, and transactions in one lightweight jar file with no dependencies.
Apache PhotArk is a photo gallery application including a content repository for the images, a display piece, an access control layer, and upload capabilities. The idea is to have a rigid design for the content repository with a very flexible display piece. The images in the content repository will be protected with granular access control.