How to integrate facebook "become a fan" box into a website??

Im not exactly show what this is called but have a look at
http://www.alexandraburkeofficial.com/gb/

How do you integrate this face book app into your website??
Can any body point me in the right direction?

Thanks for your help?

Facebook has a widgets section.

http://www.facebook.com/facebook-widgets/

You can only use the Become a Fan widget if you've created a page or app on facebook.