There was an ancient RPG.net thread, as well as a bit of my links. So I thought I'd share.
http://www.laboiteverte.fr/portraits-de-criminels-australiens-dans-les-annees-1920/ - Mugshots from Australian Police
http://collection.hht.net.au/firsthhtpictures/resbyfield.jsp?term=New+South+Wales.+Police+Dept.+&field=AUTHOR&searchtable=&displayFormat=TABLE - This is where the photos in first link come from, but there are thousands of various here. Good also for locations.
http://csac.buffalo.edu/mirrors/mirrorsimages.html - Arkansas Prison Mugshoots
http://www.iheartfaces.com/ - Photography website, lots of shots.
http://strangeraday.blogspot.com/ - Random photo every day
http://muslimswearingthings.tumblr.com/ - Name says it all
http://www.flickr.com/photos/library_of_congress/sets/72157625520211184/ - American Civil War portraits.
http://spitalfieldslife.com/2011/04/02/spitalfields-nippers/ - Victorian street urchins
http://mydaguerreotypeboyfriend.tumblr.com/ - The name says it all again
And character actors and actresses:
http://www.imdb.com/list/eV8-oqaVf54/
http://www.imdb.com/list/1ylxy9T2-J4/
Terrific. Love to plunder those for NPCs.
That Spitalfields children link was really sad.
Really interesting!
RPGPundit
Definitely useful to pull photographs.
To keep them constant I used photographs from imdb that were restricted to the silent era. It made for fairly consistent looking sheets. It worked really well, and they all had a consistent look to them that tended toward heroic.