1.Suggest he joins - it's no cost, straightforward, he has nothing to loose and much to gain from it being easier to navigate the site.
2.
From Wikipedia, looking at ways to pack spheres (balls)
Sausage packing
An arrangement in which the midpoint of all the spheres lie on a single straight line is called a sausage packing, as the convex hull has a sausage-like shape. An approximate example in real life is the packing of tennis balls in a tube, though the ends must be rounded for the tube to coincide with the actual convex hull.
Of course, Sausage packing differs from Pizza packing ...
