I've been looking at the Android + App Engine source code from a Google IO session (Android meet App Engine). They generate three projects, an Android project, a GWT interface, and an App Engine server project. All of these projects have a common source folder called shared where they can put their synchronized data classes that all parts of the app need to know about.
I'm wondering how to create that shared source folder in a general Eclipse project. How can I create a source folder in one project that's also available to and synced with other projects in Eclipse?
Edit
I'm not looking for how to do an Android Library project (I already use several of those for my apps). Android Libraries don't work for a general eclipse project, say an App Engine server side project.