The Create/SPOT interface board plugs directly into the 25-pin connector in the Roomba Create cargo bay and connects via included 20-pin cable to the Sun Microsystems SPOT controller.  The interface board level shifts the signals properly for communication between the 5-volt Create and the 3-volt SPOT and provides ample breadboarding space for adding additional circuitry.  Four modular connectors are provided for easy connection of external sensors such as ultrasonic sensors.  $89, including 20-pin cable (SPOT and sensor not included).  Packing and USPS priority mail, $9.50.