Or, to put it a slightly less wildly inaccurate way, make-live is a brilliant Debian application for creating an up-to-date Debian live CD. What is a "live CD", you ask? Well I'll tell you. Or, rather, I won't. Sorry.
Oh, ok, dammit, take a look here: http://en.wikipedia.org/wiki/Live_CD and don't say I never do anything for you. Instead, please say that I rarely do anything for you - it's more accurate, and makes you look kind of generous. Trust me, I know about stuff.
Anyway, once you've installed make-live (apt-get install live-package) you can just type "make-live" to automagically build an iso of your very own Debian live CD. It really is as simple as that. Well, it is that simple if you don't mind downloading all of the required packages each time you wish to build a CD. This can be hundreds of MB at a time.
To avoid this, you're going to want to use some kind of proxy on your local network, or your local machine. I recommend apt-cacher (apt-get install apt-cacher). Then you're going to edit (as root) the file at /etc/make-live.conf and change the various repositories to point at your proxy. For example, using apt-cacher on the local machine, you would change the following line:
Now each package will only be downloaded once. If I were not quite so lazy I would point out here that this is also a very useful method to avoid unnecessary downloads if you have more than one Debian machine on your network. But I won't, on account of aforementioned laziness.
To build a KDE based live CD, instead of typing "make-live", type "make-live -p kde" or "make-live -p kde-extra" to get extra stuff. There are also Gnome and XFCE versions of the above command.
The configuration file includes options to specify additional packages to be installed (Firefox is a popular example. Well, it is popular with me. Ok, I thought about adding it but didn't bother.), additional files to be included in the image, Which Debian distribution is to be used (unstable is the default), and other stuff that I am not going into right now on account of it is all rather complicated and did I mention I am lazy? Thought so.
So, there you have it. Now you can build your very own