Finch Controls Finch
Create a program that uses two Finches. The first Finch will be a controller for driving the second Finch. Read the x and y values for acceleration from the first Finch, and interpret these values such that tilting the first Finch down causes the second Finch to drive forward, and tilting the Finch's left or right wheel down causes the second Finch to turn left or right.
It might be helpful to mark which Finch is which by lighting their beaks different colors.
Extension: Make the controlled Finch smart by using the obstacle sensors to prevent it from running into any obstacles even if the controller drives it towards an obstacle.