Michael I do think that Marco's script can be very useful as to the thing that I did mention (I learned about its existence just now) but, still, I think that a very simple 'select same' command would be very helpful: you just select a curve, an edge, a face or an object and then click 'select same' and, there, you have selected all the same curves, edges, faces or objects in the working space!

Below I am putting a simple explanatory image. What we do in such a case when we do want to select all the similar faces -as the selected one- on such an object (other than selecting them one by one)?