In general, the answer is yes, and depending on what you know about building a live system or even a bootable CD you can call it "horribly complex" or "pretty easy".
The issue is that the liveCD / CD installer must be usable on just any piece of hardware. It needs to check the hardware, recognize it, and select the appropriate drivers, and then produce the apropriate configuration files for your system to boot up. Therefore this liveCD system cannot be simply the image of your running system, where this has already happened during installation.
There are several tools in debian / Ubuntu systems that allow you to create such CD images. What one does is to create a folder, and within that folder make a complete, customized Ubuntu install, including, for example, any additional packages, specific config files etc.
A detailed guide can be found here.