Free Download: rigstudio.com/tools/rsobjectsinpath/
This tool allows to duplicate objects and distribute them uniformly on a path.
With this tool, you can select 3 basic object types (Empty Group, Locator & Joint) or a scene object and the number of times they will be duplicated.
It has several options: to mantain position or orientantion constrain, keep the global orientation and hierarchy new objects.
This tool can also be used to modelling.
You can also duplicate a scene object in a path, specifying if you want to create a duplicate or an instance. When the scene object is a curve type it allows to create a loft (poligonal or nurbs) and if you are using an instance you can modify the original object to affect the instances.