This updates the whole system but downloading delta rpms(difference between the older rpms and newer).

Is there anything like that on Debian stable/testing/sid ?

Not really, what you can do is disable recommends and suggests.

In your /etc/apt/apt.conf put

APT::Install-Recommends "0";
APT::Install-Suggests "0";

OpenOffice.org seems to be one of the biggest updates, and it updates often. if you have a version that works for you; you can always put it on hold.

if you are on stable you shouldn't have many updates, since stable only gets security updates and bug fixes. testing and sid on the other hand tend to have updates pretty much daily.

You can also just use debsecan - http://www.enyo.de/fw/software/debsecan/ and the aptitude upgrade command rather than full-upgrade .

OpenOffice updates often? Don't think I've had an OpenOffice update yet, granted I'm using Fedora 12 but still, even on past systems. I know OpenOffice is big but I wouldn't say it updates often if you're getting it from the repos.

Fedora isnt Debian sid, OpenOffice packages tend to upgrade quite often, this week alone I have had 3 updates, all around 100MB. No problem for me as I have a decent broadband connection and my bandwidth isnt limited, but in other countries where people's bandwidth is limited its a big deal.

Sid has updates pretty much daily, depending on what packages you have installed.

The only thing that comes to mind is a Debian system, say Stable/Lenny, using mixed branch repositories with apt-pin enabled.

Apt-pin enables one to do a normal update on the stable Debian system but update/upgrade a certain app/program from another branch, say Open Office from testing. Or Firefox (Iceweasel) from Sid.

Is that what you're looking for? If so, this link might help: http://www.howtoforge.com/a-short-in...to-apt-pinning

nope that is not what he is looking for. And I can't remember ever coming across something similar to the fedora delta rpm process. A crude explanation of the delta rpm process would be something like:

Normal process

Version 1 installed (10MB)
Update downloads Version 2 (15MB)
Update removes Version 1
Version 2 installed

Delta process (let's assume the increase in 5MB from Version 1 to Version 2 is the additional code)

Version 1 installed (10MB)
Update downloads the additional code for Version 2 (5MB)
Update applies additional code to Version 1
Version 2 installed