This is apropos of nothing, but I have been meaning to link to these for some time and want to do it before I forget again… Filmmaker Errol Morris has been writing at the NY Times in a fascinating occasional series where he takes a single photograph or image and spends a few consecutive days delving into the depths of history (and mystery) behind it. He has done three of these so far:
Which Came First, the Chicken or the Egg (about a famous Crimean War photograph)
Whose Father Was He? (about a family photo found on a Civil War battlefield)
Bamboozling Ourselves (about Nazi-era Vermeer forgeries)
I love his approach, which is both rambling and minutiae-obsessed at the same time.