Saturday I was faced with the following question: how to install 10 identical ubuntu stations with the same configuration and a set of custom packages. Here is the solution finally used:
1. install the basic ubuntu system, install all the extra packages (this included notably the edubuntu package add-on which is no longer a separate distribution). This should result into a complete station.
2. install remastersys
3. create the cd/dvd iso image with the backup option. This should result into a dvd/iso image containing a remastered install containing a squashfs file system with everything. This can be used to write an installation dvd.
4. install unetbootin. This was required because the original station did not had a dvd-writer so this allows to create a bootable usb stick from an iso file
5. on a new station: configure bios to boot from the usb device, install (note: this is a remaster not just a backup so you are faced with the normal ubuntu gui install which should allow to install on different systems/configurations as well)
6. repeat step 5 on all the remaining stations.