find your CPAN/Config.pm and edit it to fix urllist:

  'urllist' => [
        q[http://theoryx5.uwinnipeg.ca/pub/CPAN/],
        q[ftp://uiarchive.uiuc.edu/pub/lang/perl/CPAN/],
        ],
[download]

Somewhere there ought to be a list of these, I agree.

Update: Some googling aroung found this:

http://mirror.cpan.org/status.cgi , where you can search on your continent. lciking on a ntry that returns willl give http: and ftp: URLs that exist at that mirror. http: is simpler to use in a firewalled environment.

--Bob Niederman, http://bob-n.com