I've just uploaded a new program I'm working on. It's an icon editor that uses AJAX to provite a multi-user editing experience. At this early stage in the program, many features are missing, but there is some basic functionality.

You can select a color, then click on the grid. Your click will be stored on the server, where other people who view the page will see your work. When you change a pixel, you will see any changes other people have made to the icon. I will be adding some more real-time features and drawing tools in the near future. In the meantime, you can try to make simple pictures with the program.

http://www.sproutworks.com/pixeleditor.php