One site I read quite regularly is Damn Interesting, a site I found through my friend Brady. They usually have some great articles, but this one is just amazing.
During the early 1900s, a Russian photographer figured out a way to create color photographs from black and white film by using special plates and a filter process. Using this, he was able to take pictures like:
From: http://www.loc.gov/exhibits/empire/
The Library of Congress bought the pictures, and now has an exhibit online about them. I highly recommend checking it out!