The problem of circle packing [0] [1] is an interesting one (spatially
speaking). It addresses the following question:
"What's the optimum distribution or n circles of radius r inside a
rectangle boundary that they don't overlap with each other?"
If someone wanted to use only grass to solve that problem, what steps
would he take?
[0] http://mathworld.wolfram.com/CirclePacking.html
[1] http://en.wikipedia.org/wiki/Packing_problem