Where did you want to live when you grew up? If you're like me, you read Clarke's SF classic, Rendezvous with Rama (soon to be a major motion picture?). Donald E. Davis took what we dreamed about and illustrated it, for NASA. His depictions of O'Neill Cylinders, Stanford Tori, and Bernal Spheres are in the public domain (and make excellent desktop wallpaper).
Designing a Space Colony? Start Here. Some light Reading. Be sure to check out the artwork (more space art by Don Davis).