When I can find the time I try out various online photo editors. I've tried Picnik, Fauxto, Phixr, Pixenate and FotoFlexer.
Picnik was my favorite of the first three. It has a bright and easy interface and lots of options for editing. Turns out, a lot of those options are only on the paid account. Still, I like the capability of "painting" the filters, like black and white. (Or "unpainting", as the case may be.) It's not the perfect editor however, I had some trouble navigating the picture when zoomed in - thus the tip of the flag is still gray.
According to several reviews I read Fauxto was supposed to be the heftiest editor, with similarities to PhotoShop. I found the interface confusing. (Hint: I don't want a webpage that looks like an application in a operating system I don't use, that doesn't understand the key commands that an application would.) It didn't seem as agile as Picnik and I have been unable to open any of the pictures I saved, despite saving them as jpegs.
Phixr wouldn't let me use 2ndgenlibrarian as a username. Forget that.
Like other editors Pixenate allows you to upload right to Flickr. My favorite edit option was spirit level (being able to straighten the horizon). Unfortunately, I couldn't find a way to undo. And if you accidently navigate away from the page (or back) you have to start all over. So you can't see all the cool things I did with Stanley.
FotoFlexer was by far my favorite. It has a interface similar to Picnik's. It also has a lot of the same editing options as Picnik, only free. The only problem I have with FotoFlexer was that instead of saving a picture it saves a canvas area much bigger than the picture. It took some tinkering to open images after I'd downloaded them.
Used Picnik to adjust colors.
FotoFlexer makes Stanley an astronaut.