It features 33 of the world's tallest and most famous skyscrapers, including the Empire State Building, the Sears Tower, the Petronas Towers, Taipei 101 (currently the world's tallest), and even the Burj al Arab (on the very left). Houston is represented by two buildings on this poster: the red gothic Bank of America Center and the turquoise Wells Fargo Plaza. (And I can't help but point out that Dallas doesn't have any of its skyscrapers represented on this poster. Ha, ha!)
Anyway, there's a lot of fun skyscraper-related images and data on on SkyscraperPage, including a diagrams of the tallest existing buildings in the world, the tallest buildings in Houston, the tallest buildings in Dubai, even a diagram of the world's tallest churches. Check it out when you have a few extra minutes.