With this proxy, you can serve distributed.net clients.

It allows you to establish one of your own machines as a buffer between
your clients and one of the keyservers that are officially run by the
distributed.net organizers. This will allow your clients to waste less
time trying to connect to one of the main proxies, since the personal
proxy will already have more key blocks waiting for your clients when
they're ready.

WWW: http://www.distributed.net/download/proxies.php