downloading badges and putting it on any websites.

Heylo php pros,

I am working on a project, which requires people to register and once they
register, they can download the badges and have them on their website,
something similar to how we have 'Verisign' tested websites etc..

Can someone help me with this ?

Theres 1 more reference : http://www.globalgreencon.com/solutions.htm
If we look at the left bottom corner of the page  theres an image called
'green certified site' and something like that, is there a cool way to do
it, and how it can be done so that there is a track maintained at the admin
section too.

I am not looking for an actualy piece of code, but a direction in general.

Thanks,
Vinay