In response to the item below about Kulwant Roy, Eric Mac wrote: "The sad part of the story is how many crates of negatives/prints were tossed out by someone who had no clue of the history in them. I have purchased many boxes of slides for the cases and carousals only to find a life story in them. As someone who has a precious few pictures of my family's past, I can only hope that in the future a family member will treasure the photos I take today."
As someone who has pawed through huge numbers of old photographs and forgotten archives, I have just one piece of advice on that account: notate them.
I was in a local "antiques" cavern just recently (an ancient old warehouse that seems to rise right out of the river—wonder how they fared in the floods?) and the proprietor told me he had a collection of 12,000 old photographs. As we talked, he mentioned one old woman who brought in a bunch of old photographs. When he asked her why she was getting rid of them, she commented, "I'm sure I'm related to some of 'em—I just don't know which ones."
To be of interest to historians or descendants alike, pictures need to be identified. So, wherever and however possible, attach some information to the picture. I know I'm like a broken record about this, but it's a point that bears reinforcing.