Refer a Friend

Hello

I was just wondering if there was any module that assimilates this:

http://recommend.eztools.com/refer.php

I wish to have a box like that in the bottom of my page so that people can refer the page they are seeing and send it to there friends... I have search the modules and i do not find any... I just would like to know if there is one and if there is not what possibilities do i have to do something similat

thanks