fd's Flickr Toys: Do fun stuff with your photos
Fun things to do with digital images
Flickr: The Commons
Copyright-free images from the Library of Congress and a number of museums and other organizations. Primarily historical photos, with lots of great primary source material.
Flickr: Will Lion's Photostream
Inspiration for effective use of text with visuals to create powerful messages
Flickr: The Stick Figures in Peril Pool
A collection of photos of sometimes bizarre warning signs. I have to find some ways to use some of these in presentations.
Blank Cell Images - an album on Flickr
Cute idea for comics or scenarios--create scenes with lego people or other toys. These images are licensed CC-By-NC-SA. This photographer also has an album with some of the same images and talk boxes already added.