Since digital cameras require more light than film cameras, the shutter is often open longer. This can cause your pictures to blur. Using a tripod or monopod can help you keep your camera still.
Also, on most digital cameras, pressing the button halfway will focus the camera. You can hold the button in this position until you're ready to take the picture. This can further reduce the time between when you press the button and when the shutter opens. It can also let you keep the camera in focus while re-framing the picture.