The trick in taking an action shot is to take the SLR out of autofocus mode. It takes too long for the camera to decide where the focal point is and, by the time it does, it's too late. Set an average focal point before the action happens and hope the subject stays in that range (a little out-of-focus is hard to see in that kind of a shot). You may have to bump up the shutter speed but I've usually found that the default is satisfactory with a flash or in bright sun. This photo was taken after teasing Squid ( www.squidgallery.com ) into jumping off the back of the couch after a toy. The camera was in a manual focus mode, the shutter speed was set manually and using an external flash gun to get enough light and a fast enough flash. His paws are clamped together right where the toy was. Notice his eyes are focused at that spot too.
http://rjknox.home.att.net/Squid_9007_23.jpg