Create Ubuntu installation of current system

I just did a clean install of Ubuntu 12.04 LTS and I almost finished configuring everything to satisfy my needs. Also I have installed several packages which are not there by default.

Is there a way to create a custom installation DVD/ISO from my current installation, so in case I want to install Ubuntu on my other computers (or restore my current one), I would just use my custom DVD and have everything configured and installed right away. I don't like spending an hour configuring and installing stuff over and over again ...

I've read some articles, but their goal was more to backup data and not to create an installation DVD.

If there are any other (simple) ways to achieve what I want, I'm all ears!

Thanks :)

Remastersys: http://www.remastersys.com/ubuntu.html

Remastersys backs everything up and creates a bootable .ISO that uses "Ubiquity" (the normal Ubuntu installer) to do an Ubuntu install.

I think Remastersys comes pre-installed on an Ubuntu installation. But if not, I at least know for certain it is in the repos:

apt-get install remastersys

EDIT: It looks like they have a GUI now too! apt-get install remastersys-gui