Cable Releases or Remote Controls
A cable release or remote control is a flexible cable that comes with a push-button switch on one of the ends. When you push the button it causes a wire running through the cable to push your camera's shutter release button. A cable release is attached right over the shutter release button on the camera. Because you don't have to hold your camera, a cable release should have hardly any effect on camera movement. This makes it ideal for avoiding camera blur in time exposures. Some cable releases also have timers built into them. Cable releases can be used for both digital and film camera models and wireless models are also available.
Some releases come in combination with a tripod. Cable releases are ideal for taking photos of subjects that are difficult to approach. Cable releases range in price from about $20 to $100.