For those who have not tried it the intersect tool is a fantastic new addition to the part modelling mode.
It lets you create a new solid from the interesection of a collection of surfaces/solids - ideal for conceptual modelling. I have attached a 2013 part I knocked up in about 5 mins showing this with a collection of surfaces, then added a rib network using the new multiple profile thin extrude (which again is a huge time saver for me).
SolidworksSolidworks 2013 Beta