I've been meaning to try out the canvas tag for quite some time. If you don't know, the canvas tag is a way of drawing vector graphics in a web browser without using a plugin like Flash or Silverlight. You can also use the tag to manipulate images--crop, pinch, that kind of thing. Its supported by every current-gen browser not called "Internet Explorer". The current interest in canvas is probably due to the iPhone whose internal web browser supports it and not flash.
Though the element is intended for static images, it can be coerced into making animations.
This is my first attempt, a simple click-sensitive animation loop: http://www.si