This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
Implementing runnable is the best way since you will get a chance to extend other class.
When you are working with AWT/Swing you must have to do this using runnable.
Otherwise it doesn't make much difference.