mvn dependency:analyze | less

It will show you unused declared dependencies, and used undeclared dependencies so you can add or remove dependencies as appropriate. Just don't go crazy with it.

Update: (mis?)Using this introduced some problems into my code because I removed dependencies whose transitive dependencies were being used. 2014/10/10 Update: The thing to pay attention to really is the used undeclared dependencies. They list the landmines where you are using a transitive dependency directly.