CentOS has been added to the USC Mirror. It's available via HTTP, FTP, and RSYNC:
http://mirrors.usc.edu/pub/linux/distributions/centos/ ftp://mirrors.usc.edu/pub/linux/distributions/centos/ rsync://mirrors.usc.edu::pub/centos/
It's updated twice a day.
This address - mirrors@linux.usc.edu - should be the contact info for this mirror.
Thanks, - Phil USC Mirror