You want to move power? We've got the SeeedStudio Relay Shield that'll let the milliamperes of an Arduino-compatible board to control up to 35VDC 70W on 4 separate channels!
The Relay Shield is an Arduino compatible smart module with 4 mechanical relays providing an easy way to control high voltage.
The max switching power is 70W DC or 35V DC. It can be directly controlled by Arduino/Seeeduino through digital IOs with external 9V supply. With the XBee form socket and 315/433MHz RF module interface, the Relay shield can be remotely controlled, making it easy to use in robotics, industry control, smart houses etc.
Note: Take care the pins on the Shield should not be touched with USB connector of Arduino UNO when they are connected.
Documentation can be found: here.