Splashup is a free online image editor that I learned about from a fellow webOS fan, Aaron Gallo, on his blog, Novacharter.
It is easy to use and even let's you "jump right in" and edit photos and images without needing an account. The controls and commands are similar to many other image editing apps so it's easy to get started. It's all online so there is nothing to download or install. It has a lot of great features and there is a light version with less features that is simpler to use.
You can save your work or share it online with different services like Facebook.
It's another great image editing tool for teachers and students.
Great, free Image editing sites and software
Two Free Graphic creation and editing software
PicMonkey - free online photo editing
Two More Free Image Editing Resources