How to create poly cylinders on all edges easily? I have a low poly model that I am trying to modify to have a constructed look to it. 



The look I am going for is similar to this where all edges are cylinders connecting the spherical vertices: (With the faces filled)



I have managed to get the spheres at all vertices of my low poly model using duplicate but I need to get the cylindrical parts on all edges between the spheres to complete the look. 

Is there a way to make this happen programatically/using functionality? I really don't want to have to do this manually.

This will be used in a game engine so needs to be geometry that can be imported so no magic rendering tricks unfortunately.
Youd could clone your mesh with Alt + D and add a wireframe modifier to it, that way the meshed are kept linked and in sync so modifications propagate.
Or as suggested by Samoth add the wireframe modifier without the option Replace Original so the underlaying mesh is kept visible

The Wireframe modifier does add a flat shaded grid with square section, so you may want to add a bevel modifier on top of it to make it smooth and cylindrical