Drawminos is a website that allows you to choose from some “Favorites”, allowing you to drop a ball, and to see the shape created by the toppled dominoes.  The part that I think will engage many students, though, is the “Create” part, in which you can design your own shape to be revealed once the ball is rolled.  It takes some planning and patience to arrange the dominoes how you would like in order to achieve your final design.  Once done, though, you can save your design online, and receive a URL for its specific location.  This could be a great way to introduce a topic, or to have students integrate their learning, their creativity, and their understanding of Physics!