One of my ongoing interests with Grasshopper is in using it as a master planning and building programming tool. This interest is reflected in my eVolo skyscraper competition entry: Anfractuo[c]ity.
Below is a GH experiment in using Voronoi tessellation to drive building massing while also keeping up-to-date calculations of all site areas areas, site coverages, and footprint areas. My goal is to eventually create a GH definition which behaves similarly to this Associative Design video.
Anyway here are some early tests: