Do this only if you know what you are doing.
Using Natty Narwhal 11.04 is nice but I want some packages from Oneric Ocelot 11.10 which is not released yet. For example newer Kernel or newer Deluge.
I do this by hacking the file /etc/apt/sources.list
Do this:
1) Take a backup copy of /etc/apt/sources.list by issuing this command:
This is NOT optional!
sudo cp /etc/apt/sources.list /etc/apt/sources.list-natty
2) Create file /etc/apt/sources.list-oneric
sudo nano /etc/apt/sources.list-oneric
3) Then add this
deb http://se.archive.ubuntu.com/ubuntu/ oneiric main restricted
deb-src http://se.archive.ubuntu.com/ubuntu/ oneiric main restricted
deb http://se.archive.ubuntu.com/ubuntu/ oneiric-updates main restricted
deb-src http://se.archive.ubuntu.com/ubuntu/ oneiric-updates main restricted
deb http://se.archive.ubuntu.com/ubuntu/ oneiric universe
deb-src http://se.archive.ubuntu.com/ubuntu/ oneiric universe
deb http://se.archive.ubuntu.com/ubuntu/ oneiric-updates universe
deb-src http://se.archive.ubuntu.com/ubuntu/ oneiric-updates universe
deb http://se.archive.ubuntu.com/ubuntu/ oneiric multiverse
deb-src http://se.archive.ubuntu.com/ubuntu/ oneiric multiverse
deb http://se.archive.ubuntu.com/ubuntu/ oneiric-updates multiverse
deb-src http://se.archive.ubuntu.com/ubuntu/ oneiric-updates multiverse
deb http://security.ubuntu.com/ubuntu oneiric-security main restricted
deb-src http://security.ubuntu.com/ubuntu oneiric-security main restricted
deb http://security.ubuntu.com/ubuntu oneiric-security universe
deb-src http://security.ubuntu.com/ubuntu oneiric-security universe
deb http://security.ubuntu.com/ubuntu oneiric-security multiverse
deb-src http://security.ubuntu.com/ubuntu oneiric-security multiverse
deb http://extras.ubuntu.com/ubuntu oneiric main
deb-src http://extras.ubuntu.com/ubuntu oneiric main
deb http://archive.canonical.com/ubuntu oneric partner
deb http://archive.canonical.com/ubuntu natty partner
4) Then replace original file
sudo cp /etc/apt/sources.list-oneric /etc/apt/sources.list
5) Do a
sudo apt-get update
6) Install packages
example:
sudo apt-get install linux-image-3.0.0-5-generic linux-headers-3.0.0-5-generic deluge
(I have also noticed that latest fglrx that is in Oneric Ocelot also works with this kernel 3 so fglrx fglrx-amdcccle can be upgraded!)
7) When you are done restore original
IMPORTANT! Dont forget this step!
sudo cp /etc/apt/sources.list-natty /etc/apt/sources.list
I wish a happy linux breaking time to the reader!