Spamdexing is not just for amateurs. It is an entire business that can incorporate all kinds of less than ethical techniques. The search engines frown on most of these techniques but the temporary boost in your ratings before you are caught is apparently worth the profits that you make.
Mirror websites are simply sites that all have the same content but use a different URL. This is a technique that is being used less as the search engines are getting better at penalizing this type of duplication.
Another clever black hat SEO trick is URL redirection. No matter what you click on the user is taken to a site that they did not wish to go for. This can backfire as often all this does is make people really angry, unless what you have to offer them is truly captivating.
Yet another popular technique for fooling the search engines is called cloaking. Cloaking refers to any of several methods that are use to offer up a different page then will be seen by humans to the search-engine spiders. Yet another tricky technique is which is a form of code swapping. Once a page has reached a high ranking in Google the code in the URL is then changed so that the surfer is taken...