A great one i found is
Picnikyou cant do text or anything but it great for editing photos
and there are certain things there that i dont know how to do on photoshop even, so its very helpful and easy to use
however it is in beta mdoe or something right now, so everything is available, but when its done, not everything will be available without purchasing an account i believe, so hurry up while it lasts haha
also, its nifty because if your computer shuts down and you werent done editing your photo it saves it and when you log in the next time it asks if you want to continue editing the last one :]