I am setting up a complete local mirror as the other mirrors are really painful to get to from the land of oz.
Also I plan on using tiny core linux for pxe booting and have worked out that a local mirror and a slightly modified initrd (adding some scripts into /opt/bootlocal.sh to make it load stuff) should do the trick WAY better than slax.
Reason I need all packages is because I dont know exactly what my pxe booting setup is actually going to do yet.
In time when money permits I will prolly setup a high speed Australian mirror to make life a little more pleasant for us aussies.
My experience with mirroring is. Basing this on a linux web host
Assuming your www root resides in /var/www create the following directory structure.
use the tree command to verify the structure (noting my present working dir is /var/www)
[root@jupiter www]# tree -d tc
1) Pick a mirror other than distro.ibbilio.org (i used ftp.vim.org) to get most of your stuff
2) Navigate to your version (e.g. 3.x)
4) Navigate to the tcz folder (note, this could take some time as generating a directory listing is pretty labourious)
5) For a full dump, copy all files inside of the tcz dir but avoid downloading the sources/src directory as they are quite large arn't needed for a local mirror.
6) When completed you'll probabally find that there are files missing, to rectify this connect to the main ftp server and then tell your client to only overwrite existing files if the source is newer. Whilst in theory it causes a load spike its short lived and its enough to get you going.
7) Check your folder permissions and then remaster your tiny core linux build so it uses your local repo.
Thats pretty much a detailed tl;dr of how to do it in easy to digest form.