Google sub-links

How do you get the sub-page listings under your site in the Google results?
Here is an example.http://www.designermagic.co.uk/google.html

Wrong! They are free. Google adds them to the #1 ranked site for certain keywords. The key is to get ranked #1 for them to show up.

Thanks for this - but my domain, designermagic.co.uk doesn't get these extra links added & I come top with designermagic as my keyword. Are they AdWord based?

No, they are based on the popularity of your sites pages. When I type in my domain in google I get the subpages added. I did nothing special to get them added.