I did a small assignment for a cycle team this evening but thought that I'd stay on and have a practise at panning.  It's been a while since I've done it and it's a skill that you need to keep up.  Basically, panning is the technique whereby you focus on and then track your subject before taking the shot so you kind of have to get a physical rhythm going.  Panning is great for denoting speed because if done properly, the background should be blurred, wheel spokes should be blurred, but most of the subject should be in focus.  It is really all about finding the slowest shutter speed that will still allow the correct focus on a moving object.   But the results are so much better than whacking the shutter speed up as high as possible and just click, click, clicking.  Wheel spokes just look frozen that way and there's no sense whatsoever of motion at all...  So it really is worth the practise....