The TeX Live net installer is a great tool. However, with a slow Internet connection it may be daunting. Think of multiple installations in a company, or imagine several users at a TeX conference or another meeting would like to install TeX Live concurrently using the meeting's internet connection.
Possible solutions would be distributing DVDs or USB sticks with a possibly slightly outdated version, using a cache such as a proxy server, or setting up a local mirror repository. Now there's another way.
Lars Madsen announced the availability of w32transplant on the TeX Live mailing list. This tool can be used to transplant a TeX Live installation from a donor PC to another PC. So you can save time, bandwidth, and costs. You even can do unattended installations on a bunch of PCs, it's not much more than unzipping and running a batch file.
The tool is already usable, though in a testing stage.
A possible workflow may be:
Install TeX Live on one PC, using the newest installer
Add all packages, tools and fonts you might need, do all adjustments which should be transferred too
Check the TeX Live tree for not needed data which would waste space also in the copies
Download and unzip w32transplant.zip and add w32transplant, w32transplant.bat and the w32transplant_support folder to the TeX Live tree (such as c:\texlive\2012)
Zip the whole TeX Live tree (using 7zip, WinZip, or another archiver)
On each other client PC, copy and unzip that file to the same place and run w32transplant.bat
Remove the copied zip file from the client PC(s)
A detailed description and the tool for downloading can be found at the w32transplant site.