Yikes, holy mail wars!
How about the PERL/CPAN methodology?
The mirror sites point all pivotal sections to *.cgi scripts
back to the mother ship: apache.org. then send "appropriate"
info back to the requestor looking for the closer node.
For instance, list.cgi does not have to be mirrored but the
documentation/src that are mirrored should point to apache.org's
list.cgi. I'm probably not making any sense without sleep. So,
take a look at the way PERL/CPAN handles it's mirror:
ftp.funet.fi/pub/languages/perl/CPAN/
and our mirror which contians links that are requests for
"directions" from it's home site.
ftp.ccs.neu.edu/net/mirrors/ftp.funet.fi/pub/languages/perl/CPAN/
Sleeep,
-Hank