The use of motion sensing to perform sophisticated command control and data input into a portable device is disclosed. A motion sensor is embedded or fixedly attached to a portable device to measure movement, motion or tilt of the device in one-, two- or three-dimensions when the portable device is used to air-write or make gestures. The use of full motion information such as rate of change of motion or tilt angle to perform functions and commands is also disclosed. In addition, the use of air-writing to input search criteria and filter schemes for portable devices to manage, search, and sort through various data, files, and information is disclosed.