Although I have heard this story many times, I have just read L. E. Read's original short essay (I, Pencil) for the first time (hat tip to Graham Brownlow). You can get a free pdf or audio copy here.
Read's short story is the autobiography of the humble pencil, and is a powerful illustration of Adam Smith's Invisible Hand - the power of the market to co-ordinate the economic activities of thousands of different people across the globe. The market is something which we too often take for granted. Too often it is wrongly maligned. We should contemplate its wonder and be thankful for the benefits it bestows on us - from the humble pencil to the iPhone. Too often we talk about market failures, but not enough about market successes. We should also be careful not to undermine the power of the market through unnecessary meddling.