I was wondering how to use constraints with an armature, i.e. have an object copy the rotation/location of a bone, or a bone copy the rotation/location of an object. How exactly would I do this?
You can use armature in Constraint parentings very easily, select the object you wan the bone to influence, add the desired constraint, and then select the proper armature.
You can also select the individual bone within an Armature object within the Constraint settings.
Not only that, you can also influence a bone's rotation via constraints: