This page is a collection of awesome public domain imagery (and sounds). Please feel free to add to it, and keep it diverse.
Ideas below:
http://www.jpl.nasa.gov/visions-of-the-future/ USE THIS LINK https://commons.wikimedia.org/wiki/Category:PD-self# THEN CLICK GOOD PICTURES
https://commons.wikimedia.org/wiki/User:Ken_Thomas Oh also anything by this guy:
Especially this series:
Historical category:
And like this:
PD by gov: https://commons.wikimedia.org/wiki/Category:Public_domain_by_government NOAA: https://commons.wikimedia.org/wiki/Category:Images_from_NOAA Guggenheim art: https://commons.wikimedia.org/wiki/Category:Media_contributed_by_the_Solomon_R._Guggenheim_Museum Where to find and surf PD: /info/en/?search=Wikipedia:Featured_pictures_thumbs_09 car ads by year: https://commons.wikimedia.org/wiki/Category:Automobile_advertisements_by_year Harry Whittier Frees: https://commons.wikimedia.org/wiki/Category:Harry_Whittier_Frees
NEW YORK IN DECADES: https://commons.wikimedia.org/wiki/Category:New_York_City_in_the_1910s
Library of Congress photos: https://commons.wikimedia.org/?title=Category:Images_from_the_Library_of_Congress&filefrom=%2A%0A17.+DETAIL%2C+TYPICAL+HANGING+LAMP+-+Union+Station030026pv.jpg
A bunch of good ones: https://commons.wikimedia.org/wiki/User:Trialsanderrors
Category: /info/en/?search=Category:Images_in_the_public_domain_in_the_United_States
can surf like this: /info/en/?search=Wikipedia:Featured_pictures_thumbs_03