I ran across a fun javascript library this weekend. It's from Walter Zorn and with a bit of tweaking you can make interactive web pages.
For the electric car weblog I made a cool Battery Layout Tool, which lets you visually organize and play with various battery and box layouts/sizes.
To demonstrate I've drag-enabled the two images on this page: click and drag an image to reposition or, in the case of tink-toes, replicate. By holding shift down and click-dragging within the battery image you resize the image.
Quite cool!