1. A computer-implemented land planning system designed to generate at least one conceptual fit and cost-optimized solution to a user-defined land development problem, said system comprising: means for electronically creating at least one candidate solution to the land development problem, said candidate solution comprising a plurality of interrelated engineering measurements applicable in development of an undeveloped land site, and said plurality of engineering measurements being selected from a group consisting of grading, building pad layout, and utilities; means for accessing cost data for said plurality of engineering measurements; means for employing an iterative, heuristic problem-solving strategy to manipulate the engineering measurements of said candidate solution until at least one cost-optimized fit solution to the land development problem is achieved, whereby a change relative to one of said plurality of engineering measurements for said candidate solution effects a change relative to another of said plurality of engineering measurements for that candidate solution; and means for outputting to a user documentation illustrating said cost-optimized fit solution to the land development problem.