Ubuntu 12.04 - Creating an installation CD from an existing installation

Hello,

I installed Ubuntu 12.04 LTS on my system. And then made a lot of changes to suit our use.

Now I would like to make an installable CD with the customized installation in my system and then use that CD to install on
many other systems. This way I don't have to do the customization on each and every system.

Is there a way to create an installation CD from the existing customized installation ?

Thanks
Karthikesh