Here's the YouTube video (1min 27sec) showing how the "race-track" memory works. Unfortunately the rest of the video is filled with pointless images that are irrelevant to the topic.<p><a href="http://www.youtube.com/watch?v=dJf3z9AfiVM" rel="nofollow">http://www.youtube.com/watch?v=dJf3z9AfiVM</a>