Sumo Paint: free professional online image editing and painting software
[youtube=http://www.youtube.com/watch?v=NAEoeWnYYvI&hl=en&fs=1]Sumo Paint brings different brushes, filters and features and will let you start painting in just a few seconds. The application loads incredibly fast and it's hard to believe you are not using a desktop application. They also provide an image gallery with really high quality pictures created using their tool.
One of the best image editing software I've tried so far. Try Sumo Paint here.