There's an interesting article in theguardian, The sparring and spin of the Google dance", which is trying to highlight the unscrupulous art of artificially enhancing your website's ranking on Google searches. However, the dilemma news organisations always face is that this kind of expose' often ends up providing the world with a "how to guide". And with the current popularity of Guardian Unlimited, it will give webmasters the knowhow that will surely exacerbate the problem.
Anyway here's the "Five ways to get to the top" as advised in the article:
Status on Google is determined by a number of factors, all of which can be faked
Good practitioners will make sure sites contain clear information that is relevant to a user search. Others will use misleading but popular keywords - such as "Britney Spears" - to try to capitalise on somebody else's fame. Some even attempt to hide fake keywords on a page so that they can be read by search engines but not by people
The more people that link to a site, the more popular it is in Google's mind. By carefully choosing who to link to and where to place those links, SEOs can push a target website up the rankings. Some shady operators even create a fake ecology of websites which all point at each other
Spamming is a tactic employed by unscrupulous SEOs, and attempts to raise profile and popularity by leaving fake messages pointing towards the target across thousands of other sites and weblogs. While unpopular with surfers, it often boosts the ranking of the site in question
Sites which seem new are often considered more important, because they are more likely to contain relevant information. Unscrupulous operators will often steal content from other pages to create the appearance of movement
Each web page carries a selection of unseen information that tells other programs what its contents are. While most SEOs simply include correct information about a given page, crooked operators will use unrelated terms to try to direct unwitting surfers