Mashable today posted about 20 Great Online Image Editors.
Many of the sites they wrote about can be found on my website under Photo-Editing (you’ll also find many more there). The Mashable post, though, has some nice screenshots and descriptions.
For my purposes, and for the purposes of my students, I don’t think there’s really much difference between any of them. You can learn more about the online photo-editing applications I’ve written about here.
You might also be interested in The Best Online Sources For Images.
One that they didn’t mention that I’ve used with great success is Cellsea http://www.cellsea.com/media/index.htm. Has a lot of the bells and whistles that the others mentioned, plus more. I think I heard about this one from you, Larry! I used it last year with classes for a project because a lot of the programs out there were blocked by our filter and this one wasn’t.