Here are some links to other sites I think you might enjoy.

Nick Stevens Graphics Blog


Nick did the graphics of the non rotating skyhoopk for the book, “Opening the High Frontier”

Nick’s Blog

NASA Advanced Concepts


The people doing it for real.

Winchell Chung’s Atomic Rockets


I’ve spent many hours exploring the vast amounts of information on spaceflight concepts and information on this site. He is VERY careful to explain the feasability limits of each concept or design discussed.

Project Rho