I don't normally mention mere plug-ins here, but this one's so cool I couldn't help myself. Jörg Spieler's Unnecessary Code Detector is an Eclipse plug-in that finds unnecessary, unreferenced public members and classes. Perhaps not so useful for libraries where you don't necessarily have all callers loaded into the IDE; but for stand-alone applications this could be very useful. I love deleting code, and anything that helps me delete more code is a tool I want in my toolbox.