Remastersys will 'remaster' your existing Ubuntu based distro into a live cd/DVD. Tools like PCLinuxOS's mklivecd have been around a while and proved to be very popular but are tricky to get working with the newer releases of debian/ubuntu, so some guy (apologies, forgot your name) over at Linux Mint (an ubuntu-based distribution) made this really cool tool. And although it has only really been in popular use since about March this year, it has already been compared to the maturity of mklivecd.
Add the Linux Mint repo to your /etc/apt/sources.list
echo "deb http://www.linuxmint.com/repository romeo/" >>/etc/apt/sources.list
do a "sudo apt-get update"
"sudo apt-get install remastersys" and it should install fine.
Then simply type "sudo remastersys" to get the list of options, which include:
backup - backs up your system including your /home folder with your users on it.
dist - omits the /home folder thus making it a distributable cd that you can give to your friends.
clean - removes the temporary folder that was created, including the new iso so burn it and copy it elsewhere before you run "sudo remastersys clean"