As far as art projects on the Web go, this one just might take the prize for the week: thissand.com allows visitors to build colorful sand castles by transforming the pixels on the screen into digital grains of sand. Click your mouse to drop the sand and use simple commands to change the color or gradiant. A soft sandy sound accompanies the process, which I find extraordinarily soothing. Once you've finished your sandscape, save it to the gallery for everyone to see. (Mine is pictured above.) Read more about the project and see some of the best creations yet at thissand.com/blog.