Being able to capture a sense of movement is a skill worth mastering because you can apply it to a wide range of subject, from sport to wildlife to shots of your kid having fun.
The most popular techinuque used to imply movement is paning. The slower the shutter speed you use, the more blur you'll record, and thought panning experts are able to keep their subject pin sharp, the result can look even more blurs too, so don't worry if this happens.
Alternatively, use a slow shutter speed and keep your camera statinory, so that anything moving across your field of view during the exposure blurs while everthing else remains sharp. This can work for wide range of subject, such as water, commuters rushing off train or people in a busy street.
taken from Digital Camera Magazine issue 03 March 2006.