It actually works pretty simply — it is simpler than the Javascript implementation. All it does is load a page (in a hidden Iframe) which contains lots of links. If a link is visited, a background (which isn't really a background) is loaded as defined in the CSS. The "background" image will log the information, and then store it (and, in this case, it is displayed to you).
http://www.making-the-web.com/misc/sites-you-visit/nojs/ Is a demonstration of a method to find out the browsing history of a visitor to a website, no javascript required. It seems the only drawbacks to this method are the increased load on your browser, and that it requires a list of websites to check against."
A prototype USB drive using bug protein to store data in the neighborhood of around 50 terabytes worth of data could be here in less then 18 months. This idea first started out by coating DVDs with a layer of protein so that one day solid state memory could hold so much information that storing data on your computer hard drive will be obsolete, says Professor V Renugopalakrishnan of the Harvard Medical School in Boston while reporting on his findings at the International Conf
Trap full -- please empty.