Aviary is a free suite of powerful online creation tools: Image editor, Music creator, Audio editor, Vector editor and more!
http://www.aviary.com/

Seamless Studio makes it easy to design a seamless pattern. With simple editing tools you can resize, rotate and add shapes, lines and text to the canvas and it tiles automatically. When done, you can save your pattern template.
http://www.colourlovers.com/seamless

The AJAX Code Playground is an educational tool provided by Google to show code examples for various Google Javascript APIs.
http://code.google.com/apis/ajax/playground/

JayCut is a free online video editor. Engage your audience with the world's premier online video editor seamlessly integrated on your website, or edit your own videos on JayCut's community.
http://jaycut.com/

It is an online image editing software similar to Photoshop or Gimp. Images can be saved to your hard drive as a .jpg, .png, .bmp, .tiff or as a Pixlr layered file to be loaded and worked on later. The software also provides the ability to save the images directly to Facebook, Flickr, and Picasa.
http://pixlr.com/editor/

Writeboard is a collaborative writing software for sharable, web-based text documents. You can save every edit, roll back to any version, and easily compare changes. Use writeboard to write solo or collaborate with others.
http://writeboard.com/