Question about "similar pages"

[Linkster]

CaptainJSparrow - I think what you are asking is how does google come up with the similar sites?

Here's a link that explains the concept genarally

and

where it came from

Originally released as Google Scout back in 1999 it basically was a techic version of "lets look at this website and who links to it - now who else do those same sites link to" - and the similar sites concept was born. Basically Google looks at who links to you and who else they link to - to try to direct the surfer in his surfing.
Its not really magical or anything - just an attempt at trying to "group" web sites together

In answer to whether it's useful for trying to perform SEO - wouldnt know the answer - Im not into SEO'ing
But it sure is nice to see who my backlinks link to - of course just putting your sig with a site in it can cause that grouping effect

<added> a check with some friends tells me that there is some theming going on in there as well - some kind of web-mapping where Google Scout tries to determine the "communities" on the web - could be good or bad I guess
Also - you might want to check some DMOZ listings and check where other "similar sites" are listed in DMOZ - seems to play into the picture