The High Power H-Bridge Motor Shield for Arduino is equipped with built-in current sensing utilizing the ACS712, and is capable of driving any DC motor up to 15Amp.

This shield could be a good alternative to hobby RC controllers for robots that need a customizable open-source motor controller. The PCB design and source code are available on GitHub.

An interesting Arduino project has been published to the Instructables website showing how an Arduino CNC shield and controller has been used to create an awesome 3 axis Arduino CNC plotter.