Acá está mi último listado de repositorios, con todas las llaves extrañas encabezando el repositorio con un comando que baja la clave y la agrega automáticamente.

Copiar y pegar:

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

deb http://cl.archive.ubuntu.com/ubuntu/ feisty main restricted
deb-src http://cl.archive.ubuntu.com/ubuntu/ feisty main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://cl.archive.ubuntu.com/ubuntu/ feisty-updates main restricted
deb-src http://cl.archive.ubuntu.com/ubuntu/ feisty-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## universe WILL NOT receive any review or updates from the Ubuntu security
## team.
deb http://cl.archive.ubuntu.com/ubuntu/ feisty universe
deb-src http://cl.archive.ubuntu.com/ubuntu/ feisty universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://cl.archive.ubuntu.com/ubuntu/ feisty multiverse
deb-src http://cl.archive.ubuntu.com/ubuntu/ feisty multiverse

## Uncomment the following two lines to add software from the ‘backports’
## repository.
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
# deb http://cl.archive.ubuntu.com/ubuntu/ feisty-backports main restricted universe multiverse
# deb-src http://cl.archive.ubuntu.com/ubuntu/ feisty-backports main restricted universe multiverse

deb http://security.ubuntu.com/ubuntu feisty-security main restricted
deb-src http://security.ubuntu.com/ubuntu feisty-security main restricted
deb http://security.ubuntu.com/ubuntu feisty-security universe
deb-src http://security.ubuntu.com/ubuntu feisty-security universe
deb http://security.ubuntu.com/ubuntu feisty-security multiverse
deb-src http://security.ubuntu.com/ubuntu feisty-security multiverse
deb http://www.getautomatix.com/apt feisty main

## Repositorios LG3D ##
deb http://javadesktop.org/lg3d/debian stable contrib
# deb http://javadesktop.org/lg3d/debian testing contrib
# deb http://javadesktop.org/lg3d/debian unstable contrib

## E17 repository «edevelop.org»
# wget http://lut1n.ifrance.com/repo_key.asc -O – | sudo apt-key add –
deb http://edevelop.org/pkg-e/ubuntu feisty e17
deb-src http://edevelop.org/pkg-e/ubuntu feisty e17

## Oracle Xpress Edition
# wget http://oss.oracle.com/el4/RPM-GPG-KEY-oracle -O- | sudo apt-key add –
deb http://oss.oracle.com/debian unstable main non-free

## Treviño
## wget http://download.tuxfamily.org/3v1deb/DD800CD9.gpg -O- | sudo apt-key add –
deb http://download.tuxfamily.org/3v1deb feisty 3v1n0
deb-src http://download.tuxfamily.org/3v1deb feisty 3v1n0

## KUBUNTU.ORG KEY
# wget http://people.ubuntu.com/~jriddell/kubuntu-packages-jriddell-key.gpg -O- | sudo apt-key add –

## kubuntu.org packages for the latest KDE version (GPG key: DD4D5088)
deb http://kubuntu.org/packages/kde-latest feisty main
deb-src http://kubuntu.org/packages/kde-latest feisty main

## kubuntu.org packages for the latest amaroK version (GPG key: DD4D5088)
#deb http://kubuntu.org/packages/amarok-latest feisty main
#deb-src http://kubuntu.org/packages/amarok-latest feisty main

# Official Beryl Ubuntu Packages (GPG key: 1609B551)
# GPG key-file: http://ubuntu.beryl-project.org/root@lupine.me.uk.gpg
# wget http://ubuntu.beryl-project.org/root@lupine.me.uk.gpg -O – | sudo apt-key add –
deb http://ubuntu.beryl-project.org feisty main
deb-src http://ubuntu.beryl-project.org feisty main

#AUTOMATIX KEY
# wget http://www.getautomatix.com/keys/automatix2.key -O- | sudo apt-key add –

#AUTOMATIX REPOS START

deb http://archive.canonical.com/ubuntu feisty-commercial main

deb http://archive.ubuntu.com/ubuntu feisty-backports main restricted universe multiverse

deb http://archive.ubuntu.com/ubuntu feisty-updates universe multiverse

deb http://archive.ubuntu.com/ubuntu feisty-security main restricted universe multiverse
#AUTOMATIX REPOS END