I just noticed a comment on one of the photographs. A patron recognized another patron's house, and forwarded him the link to our historical photograph. The second patron then uploaded a photograph of his house today to his flickr account, and linked the two together using comments.
That's great - that's exactly how libraries can enrich their collections and communities. We didn't really do anything, other than put our pictures out there (no real promotion or involvement after that). It was word-of-mouth between patrons that brought this about, and let the library be involved in their daily lives. Neat.
And for those looking for meaning in life: note the sign in the foreground of the "today" photograph.