I came across Newton's Cradle in the Appstore the other day, and at the sight of seeing it, it brought back memories, so I downloaded it immediately.

I use to have one long ago, and for some reason, I fell in love with watching it, and seeing the different patterns I could get the swinging balls to bounce against each other.

Now modernize in form of an iPhone app, this popular executive desk toy is loads of fun. Not only can you swing the balls like it is sitting on a desk, but just like if you picked up the real version, gravity takes over and they swing in the way you lean it. Amazingly this is part of the app, and as you move your iPhone, the balls swing as if gravity took over.

Additionally, the other night I synced my iPhone, and was alerted that there was a Valentine's Day update for Newton's Cradle. After updating the app, I can now choose to have swinging Hearts that spell out "I Love You" instead of the steel balls. How cool...