Getting a perfect sphere in Blender? I'd like to create a sphere using a cube as a starting point. The way I'd normally go about that is to add a couple of subsurf modifiers and then apply them, however, this does not give a perfect sphere.

I recall seeing somewhere that somebody used a command after this process to make the rounded cube perfectly spherical, unfortunately I do not remember what this is.

Could somebody please inform me how to create this spherical shape in Blender using this basic technique?
Non-destructive way would be to use Subdivision Surface modifer along with Cast modifier set to Sphere > Factor > 1.