I'm a fan of refactoring, and I pretty much always hit Ctrl-Shift-O in Eclipse (organize imports). It's such an easy hit, and removes a few compiler warnings. Little did I know that there's a much better way: Guide to refactoring in Eclipse 3.2.
I'm not sure how I managed to miss that wizard, but the Clean Up wizard will actually clean up the imports, remove unused variables and more for your entire project.
My favorite Eclipse refactoring shortcut is still "Extract Method", though.
Thus, I was excited to see that usability expert Jakob Nielsen says that breadcrumbs are becoming increasingly useful. In some cases breadcrumbs can even remove the need for a back button.