I am using Pound as a HTTPS frontend for my secured website.
I have read an interesting article about Apache and its "client
authentication using client certificates":

http://www.securityfocus.com/infocus/1823

This article describes how to set up Apache to accept only connections
from clients that own a specific certificate.
So only trusted persons (ie. persons who have that certificate on
their web client) can access the website.

Does Pound have that feature?