GlassGiant.com - Make pictures for your Facebook Photos!
Some silly photo editing and image creation tools. More useful ones include creating a keyboard button with any word you want on it (Smite is the example given) and a chalkboard with a message of your choice. I could do these in Photoshop, but this would be easier.
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.
Lifehacker - Five Best Online Image Editors - Image Editing
Five online applications for editing images: Sumo Paint, Photoshop Express, Pixlr, Picnik, & Aviary Phoenix. All have at least some free options, although premium accounts are required for some features.
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.
Sites with High Quality Photos You Can Use for Free | CSS-Tricks
Free photos. This list includes a number of sites I haven't seen elsewhere. Many of these just share a few photos each week, and you'd have to be pretty creative to use them for most corporate e-learning. This isn't just typical stock photos.
Body Liberation Stock: Body-Positive & Size-Diverse Stock Photos for Commercial Use - Body liberation boudoir, portraits, stock, HAES & more | Seattle
If you need more diversity in stock images, this site has a range of body sizes and people with visible and invisible disabilities. Images start around $5 each, which seems pretty reasonable (and much better than the $40/image I have seen on some other specialty sites).
Freepik's images require attribution, but this is a popular site for finding free images. A paid subscription removes the need for attribution. This site has a collection of illustrated character creation sets, where you can assemble a character with expressions and poses