Photoshop CS5 Release Party
The original image can be found as american_cities_75.jpg on the National Archives, and is in the public domain.
I used Photoshop CS5 Extended's Repoussé tool to generate the 3D text in the marquee. The shadow is live, and is cast onto an invisible 'shadow catcher' plane behind the text. The Text Warp tool is responsible for the arc in the text, and I used the new Content-Aware tools to remove the previous marquee.
I opened up the texture files and added some detail to the diffuse and bump maps, then finished the composite with some overlaying texture and simulated film grain and damage.