One technology which I would like to use to do something productive (read: find a client who pays me to write an application) is JCR (Java Content Repository).
The JSR-170 specifies the way which we would use to communicate with the content repositories. The content repositories or "Content Management Systems" (CMS) like Documentum or Vignette, allows us to save binary or textual information without worrying about where it happens, might be a relational database or XML files.
But every vendor has his own product and his own way of access that information, that's why JSR-170 tries to fix the problem of standardization.
In the open source world, Apache JackRabbit is the reference implementation.
The information is organized as a tree of nodes, with each node having "attributes" or "properties" where to save the data. For example, to save information we do as following (example taken from here):
Session session = JackrabbitPlugin.getSession();
Node rootNode = session.getRootNode();
Node blogEntry = rootNode.addNode("blogEntry");
With this code we would manage to create a node, make it versionable (one of the JSR services), fill it with our information and save it.
You never know, in the near future I may convince somebody to use Jackrabbit. Wish me luck!