Vertical vs Horizontal Living

Most of the time I live in a horizontal world, driving from place to place or walking from place to place. But I have been living in a hotel in Kuwait for some time now and today when I was heading back from the 8th floor Club Room to my room on the 3rd floor I began to think about what it would be like to live in a vertical world where you lived, worked and played on vertical planes. Whole cities that you used elavators and escalators to move up and down from store to office to home. Would be a better use of space I think. Think I'll head down the the first floor and get some dinner and ponder this some more.