Since there are probably a lot of people that mirror CPAN, but are not official mirrors, here is an email recently posted on the CPAN mirrors admin list:
Date: Fri, 15 Aug 2003 18:19:53 +0300
From: Jarkko Hietaniemi <jhi@iki.fi>
To: cpan-mirrors@perl.org
Subject: North American CPAN mirrors
(All non-North American CPAN mirror admins are free to ignore this message.)
If you are mirroring from funet.fi...
the admin of the pair.com CPAN mirror told us that they have nowadays a Really Big Pipe to the Internet, and that they could easily handle more download traffic. Therefore you might to try whether you could get better mirroring bandwidth from pair.com than from funet.fi, and if you do, you could switch over to pair.com. (At the same time I think we could also increase the mirroring frequency of pair.com itself.)
In addition to this, I should also note that even though we aren't listed as having rsync available yet, you can rsync the entire CPAN archive from 'cpan.pair.com::CPAN'. Cpan.pair.com is now mirroring funet several times a day.