Creating an ISO from INSTALLED UBUNTU.

[elmo]

I have a 8,04 DVD version installed.  I have done a lot of customizing 
it, (full desktop, some additional software, for example), so it's 
considerably larger than it was when I first installed it. In its 
present size, it would definitely require a DVD to hold a copy of it.

Instead of spending a lot time in my making copies of it on my DVDs. I 
would like to be able to send the whole package via email to 
acquaintances in ISO form and let them make their own DVDs.

There's a lot of info about burning ISO Image disks but a scarcity about 
the reverse process, ie., create an ISO from a working program.

HELP!!!

Elmo