halp!

ben@Athene:~$ sudo apt-get -f install
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 6 not upgraded.
1 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Setting up apt (0.8.16~exp12ubuntu10.11) ...
ERROR: Can't find the archive-keyring
Is the ubuntu-keyring package installed?
dpkg: error processing apt (--configure):
 subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
 apt
E: Sub-process /usr/bin/dpkg returned an error code (1)