Newton’s USB Cradle is the replication of the original Newton's Cradle. We all remember the device with five marbles that swing back and forth. Now it is in the form of a USB. The device has 4 USB hubs, instead of 5 because a USB is larger than a marble. It comes with a power supply to plug into an outlet in order for it to work. There has been some speculation as to whether or not it works. The selling price is $24 at buy.com.