I'm experiencing an odd sort of Newtonian convergence today. I'm reading Gleick's Isaac Newton, including descriptions of the many things he observed and read and wrote about in his notebooks, observations that led to his laws of motion (not to mention the calculus and other major topics in physics).
I'm also re-reading sections of Seymour Papert's 1980 book Mindstorms (subtitle: Children, Computers, and Powerful Ideas). In fact I've just read the chapter called "Microworlds: Incubators for Knowledge" in which Papert discusses how computer-based "microworlds" can provide children with a way to gain direct experience with "laws of motion" including Newton's famous three Laws of Motion. It's easier and less abstract when you have actually played with objects that behave in a Newtonian fashion (as opposed to objects like real blocks that tend to not continue in motion at a constant speed after you apply a force to them with your hand - friction makes Aristotle's ideas of motion seem more plausible at first to most people). You can also play with laws of motion other than Newton's, and if you have explored a "Turtle geometry" microworld, you will already be familiar with some "laws of motion" though you may not have called them that (e.g., the FORWARD 10 command moves the turtle by the 10 steps in its current direction, and the TURN 30 command changes the direction by 30 degrees).
Papert used Logo in his microworld education work, and I'm now using Etoys, which in many ways is a direct descendant of Logo. My evolving "Moonhopper" project is basically a prototype microworld for playing with Newtonian physics. I still have a lot to figure out on this, not so much about how to simulate frictionless motion with gravity and rocket thrusters (this is pretty easy in Etoys), but on how to structure this into a teaching unit so a middle school kid can follow a general game plan and discover these powerful ideas for him or herself. This is exactly the kind of exploratory learning that Papert discusses in Mindstorms and that the Etoys/Squeak and similar environments can encourage.