Howtogeek posted a tutorial about creating your own customized Ubuntu Live CD

We love Live CDs, but it's a hassle installing the same packages every time you need to do a virus scan or recover accidentally deleted data. We'll show you how to roll your own Ubuntu Live CD, with all the packages you want, and even more nice customizations. The tool that we're going to use is called Reconstructor, which is a free webapp that lets you roll your own Ubuntu and Debian CDs.

How to Create Your Own Customized Ubuntu Live CD