Historypin is a social media website where you can "pin" photos, stories, video and audio clips to a map of the world. While there are individuals using Historypin there are also repositories using it to highlight their collections such as the National Archives. Historypin can be browsed by collection or by location. I have also found it useful to Google a keyword and the word 'Historypin' to find what I specifically want.
Historypin does include church photos. New York Historic Churches is a nice collection of 19th century church building photos, with information about each church. As you take the "tour" of this collection it also includes a Google Map that shows where each church is/was located.