How to make 1 DVD from 3 FreeBSD CDs?

Everybody knows how long it takes to install and mostly because one has to joggle with 3 CDs: it doesn't work like pcbsd: disk1 then disk2 and that's it. We must repeatedly change disks during installation.
Unfortunately our developers don't offer us a DVD. It could be many reasons for this but on the other hand why don't they offer us a simple script "doityourself"?
I found such a script but it works not stable because it depends on some "el-torito" special boot image and I couldn't find it on Internet. But anyway I'm able to create a bootable DVD from 3 (and even 4) CDs. I'm just not brave enough to suggest it for others.
May be somebody knows proper working script?
Code is from Dru


# extract all ISO for creation 1 DVD disc
# set path to our ISO's

# extract all from archive
echo "Extracting disc $cd3"
tar -xf $cd3 -C /home/<user>/ISO/all
echo "Extracting disc $cd2"
tar -xf $cd2 -C /home/<user>/ISO/all
echo "Extracting disc $cd1"
tar -xf $cd1 -C /home/<user>/ISO/all

# chage INDEX
echo "Change INDEX"
sed -ie 's/|2/|1/g' /home/<user>//ISO/all/packages/INDEX
sed -ie 's/|3/|1/g' /home/<user>/ISO/all/packages/INDEX

# creating dvd-iso
mkisofs -v -J -R -no-emul-boot -b boot/cdboot -o /home/dik/tmp/7.0-RELEASE-i386-dvd.iso /home/<user>/ISO/all

I use this script myself just have to change the iso to what ever version you want.
Wow, Kitche, it's the same script I mentioned!
The problem is that it worked for me excellent 1st time and then failed (???) then I made iso using only sed and mkisofs, last time it miraculously did everythnig but tar operations (I untared manually). That's why I didn't want to post it here :)
As I was told file boot/cdboot is special el-torito file (boot image) and unclear how to get it... not quite comprehensive though: it worked somehow.

I read that thread, thank you, Susanth, but it looks too much job to just combine 3 CD's in 1 DVD.

Well thanks our developers: after 7.1 my question will be obsolete! For FreeBSD, but in general the question persists...
Alternatively, you could extract the package files and store them somewhere (a DVD works, but an USB stick might be easier and faster). If you then do a minimal install from disc 1, you can boot that, mount the DVD/usb stick/whatever, and use pkg_add to add the packages you want.

Slightly less elegant, of course.
(Personally, I just use ports or pkg_add -r after installing, but I imagine that's less fun if you've got a slower line or a download cap.)

edit: I guess the computer you're creating the DVDs on isn't on the same network as the one you'll be installing on? If it is, you could just extract the packages into a folder and NFS export that, then mount that and install from it on the other one (after doing a minimal install).
Thank you, Djn, its very useful with usb. I also tried ports but it was really slow: despite I have high speed and 20GB of monthly free download bandwidth it took me hours to get Gnome perhaps because the server trafic we all depend on.
As to the script it's indeed from Dru's blog but it's not her script, it's from (Russian).
Anyway I don't understand why it doesn't work steady (the same network but I tried even on the same machine). I'll try to contact those Russian guys.

Zeiz you said that it worked the first time for you and then failed, just ondering if you could elaborate on what actually happened or whether you had managed to find out why it failed? I'm thinking of trying that but i don't want the same thing to happen to me!

Thaks in advance.

I've been waiting to get your response zeiz but i haven't received on yet just wondering if you are oging to respond whether through on here or Pm??