**************************************************
Ubuntu Privacy Remix (UPR) is a modified live CD based on Ubuntu. Its goal is to provide a completely isolated working environment where private data can be dealt with safely and to protect data against unsolicited access. Networking is intentionally disabled and saving data to mounted volumes is not allowed. The live CD is not installable to hard disk.
I was going to say that you could do this on previous releases of Ubuntu, just this one you can’t install. Also, knoppix can work this way if I’m not mistaken.
KINGWIN KF-91-BK SATA Black Aluminum Mobile Rack
There are other options...
I am assuming that the sofware would let me write to a mounted disk.
I don't get it. How are you going to have any persistent data to work with, or has the term "mounted volume" been abused?