Implementors plugin

This plugin gives the ability to go to the class that implements an interface. It adds a new right-click menu option called "Open Implementation".

Project homepage: http://eclipse-tools.sourceforge.net/implementors/
Automatic update URL: http://eclipse-tools.sourceforge.net/updates/

Just install the plugin. Then, when you restart Eclipse, you should be able to use it. Right click on an interface and you should see the "Open Implementation" menu item.