[Update 2014-09-02]: Since this original post, a plugin has been made for Android Studio/IntelliJ by Michał Charmas with contributions from me as well. See android-parcelable-intellij-plugin for installation instructions.

I have created a tool for making the methods needed for implementation of Android's Parcelable interface within a pre-existing class.

  1. Open the parcelabler tool.

  2. Copy the full code of the class into the "Code" text field.
    Example code: 

     public class Photo {  

    /**  

     * Caption for the photo  

     */  

    public String caption;  

    public int commentCount;  

    public long photoId;  

    public boolean isDefault;  

    public Bundle metadata;  

    public CommentHandler commentHandler;  

}

  3. Click "Build" to create the methods

  4. Copy the methods into your class

  5. Add implements Parcelable to your class definition

Now you should hopefully have a working implementation of Parcelable in your class.