This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
You have to implement a public clone method (being less restrictive is fine) but if you have an option stay away from the brain-dead clone implementation and just add your own public copy method. I have no direct knowledge of this but it would not surprise me to discover that the person who added the clone interface in Java was a programming intern high on crack.