I was having a conversation with my father and father-in-law, both of whom are in electric related work, and we came to a point where none of us knew how to proceed.  I was under the impression that electricity travels on the surface while they thought it traveled through the interior.  I said that traveling over the surface would make the fact that they regularly use stranded wire instead of a single large wire to transport electricity make sense.  

If anyone could please explain this for some non-physics but electricly incline people, I would be very appreciated. 

It depends on the frequency. DC electricity travels through the bulk cross section of the wire. 

A changing electrical current (AC) experiences the skin-effect where the electricity flows more easily in the surface layers. The higher the frequency the thinner the surface layer that is usable in a  wire. At normal household AC (50/60hz) the skin depth is about 8-10mm but at microwave frequencies the depth of the metal that the current flows in is about the same as a wavelength of visible light

edit: Interesting point from Navin - the individual strands have to be insulated from each other for the skin effect to apply to each individually. That is the reason for the widely separated pairs of wires in this question What are all the lines on a double circuit tower?
