A method, comprising: detecting motion of a device in response to receipt of a signal from an accelerometer disposed in said device ; characterized in that the method further comprises: changing a power state of the accelerometer in response to receipt of the signal from the accelerometer ; changing a power state of a gyroscope , also disposed in said device , from a sleep mode to a normal operational mode to perform a measurement activity in response to said detecting said motion of the device, the sleep mode being different from the normal operational mode, wherein said changing the power state of the accelerometer comprises changing the power state of the accelerometer from a low-power mode to a normal operational mode in response to detecting said motion of the device in order to perform the measurement activity in conjunction with the gyroscope, the low-power mode drawing more power than in a sleep mode to enable limited functionality of the accelerometer ; and changing the power state of the gyroscope back to the sleep mode, and the power state of the accelerometer back to the low-power mode, upon completion of the measurement activity. detecting motion of a device in response to receipt of a signal from an accelerometer disposed in said device ; characterized in that the method further comprises: changing a power state of the accelerometer in response to receipt of the signal from the accelerometer ; changing a power state of a gyroscope , also disposed in said device , from a sleep mode to a normal operational mode to perform a measurement activity in response to said detecting said motion of the device, the sleep mode being different from the normal operational mode, wherein said changing the power state of the accelerometer comprises changing the power state of the accelerometer from a low-power mode to a normal operational mode in response to detecting said motion of the device in order to perform the measurement activity in conjunction with the gyroscope, the low-power mode drawing more power than in a sleep mode to enable limited functionality of the accelerometer ; and changing the power state of the gyroscope back to the sleep mode, and the power state of the accelerometer back to the low-power mode, upon completion of the measurement activity. changing a power state of the accelerometer in response to receipt of the signal from the accelerometer ; changing a power state of a gyroscope , also disposed in said device , from a sleep mode to a normal operational mode to perform a measurement activity in response to said detecting said motion of the device, the sleep mode being different from the normal operational mode, wherein said changing the power state of the accelerometer comprises changing the power state of the accelerometer from a low-power mode to a normal operational mode in response to detecting said motion of the device in order to perform the measurement activity in conjunction with the gyroscope, the low-power mode drawing more power than in a sleep mode to enable limited functionality of the accelerometer ; and changing the power state of the gyroscope back to the sleep mode, and the power state of the accelerometer back to the low-power mode, upon completion of the measurement activity. <EOS>