@Jason / roberts / curaga / etc.
Here's a potential fix for bandwidth (TCL, Ibiblio and others) where people would not "need" a full mirror assuming there's an internet connection.
Caching Server Scenario:
Assume busybox-httpd or similar (small) web server
Add a custom CGI which catches 404's, puts the caller "on hold", fetches the requested file from a mirror, updates the local repo, then sends the file through to the caller.
This way, people can run a local repo on an as-needed basis. Figuring out which files/dependencies/etc. someone's going to need is a chore when you're building/rebuilding/testing/repeating.
Client machine:
/opt/tcemirror contains
http://192.168.111.222/tinycorelinux/
Repo Server:
/usr/local/bin/busybox-httpd runs our show
/usr/local/repowww/cgi-bin/index.cgi contains 404 downloader content
/usr/local/repowww/tinycorelinux is a soft-link to where ever the TCL repo is located