How does Google comes up with the related web pages? Whenever I search for related:www.mysite.com, all results are not related at all.
From what I've seen, if your link appears on the same page as another link frequently you will see that link in a related: query. This is a problem with buying links - as vendors often have the same sets of customers.
It might be useful for link exchange or even when buying links. The related sites might give you an idea on how relevant a certain site is to your category. my 50 cents