rsync is an advanced tool to synchronize remote directories. You can get it for Linux and Windows (probably also for Mac and further OSs), but it is a command line tool.
Here some instructions and tips how to rsync the TeXLive repository so you can set up an own HTTP or FTP server as repository for you local TeXLive.
A general description on how to rsync TeXLive can be found at http://www.tug.org/texlive/acquire-mirror.html, but I most likely read that page already.
For Windows there is e.g. cwRsync which is based on cygwin, a Unix emulation for Windows.
Another Windows HowTo to install and setup
rsync can be found at http://optics.ph.unimelb.edu.au/help/rsync/rsync_pc1.html. This is useful if you want to update your copy of the TeXLive repository automatically.
To synchronize it simply use the following command line, where
%CTANMIRROR% is a rsync CTAN mirror:
rsync -a --delete rsync://%CTANMIRROR%/systems/texlive/tlnet/ "/cygdrive/<driveletter>/dir/subdir"
So e.g., to sync from DANTE's rsync server to
rsync -a --delete rsync://rsync.dante.ctan.org/CTAN/systems/texlive/tlnet/ "/cygdrive/c/texlive/"
-a stands for archive mode (you might get some warnings that Unix/Linux permissions can't be set; that's normal and not really an issue) and
--delete will delete all extraneous files (in the local destination) which do not exist on the remote source folders.