Let me introduce to you three very different sky-bridges today. I find these a very fascinating aspect of architecture, they are usually built after the corresponding buildings and so the styles are different. All three are located in New York.
Our first example is gorgeous, I may design a pair of buildings just so I can implement it into my layout. This is located on the former NABISCO building.
The next one is also located on the former NABISCO building, but is only visible from the interior of the building, this is great reference for a more industrial structure.