The Android Parcel Project
The Android Parcel Project was a CommonsWare initiative to foster the creation of reusable Android components. It consisted of two major pieces:
A packaging system for "parcels" and tools for creating and deploying them. This was a miserable failure.
Tips for how to create reusable components that would not collide with project files (e.g., resources) or other components. This was less of a failure.
For the advice on how to create reusable components, see The Busy Coder's Guide to Android Development.
Soon (hopefully), the Android tools will support converting Android library projects into JAR files that can be distributed, indepenently of the library project's original source code. At that time, the original parcel recommendations will be revisited, and with luck, somebody will remember to update this Web page with the results.