Following a link from Seth Godin's site, Stick with me kid, I came across this interesting article on the Rugles blog regarding how Google can help people come up with appropriate search terms. The author explains how they were given a list of suggested/related words when looking for the word 'shoes'. The resulting suggestions included 'dc shoes', 'running shoes' and 'rockport shoes'; by further clicking on 'running shoes', they were presented with 'nike running shoes', 'brooks running shoes', etc.
The author noted that when they tried it out a second time, the results couldn't be replicated. I have just taken a look at Yahoo! and they do offer a similar option:

This tool could be quite useful in helping companies come up with suggestions on new keywords, for meta tags, page titles and for their site content. I would assume that the related words are generated from queries already carried out on Yahoo!
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