Ubuntu and R

I've recently installed Ubuntu 5.10 on a desktop and need R installed, 
however, even after uncommenting the repos associated with universe, 
backports and multiverse, the packages available for Ubuntu are somewhat 
out of date:

clint at simba:~$ apt-cache policy r-base r-base-core
r-base:
   Installed: (none)
   Candidate: 2.1.1-1
   Version table:
      2.1.1-1 0
         500 http://archive.ubuntu.com breezy/universe Packages
r-base-core:
   Installed: (none)
   Candidate: 2.1.1-1
   Version table:
      2.1.1-1 0
         500 http://archive.ubuntu.com breezy/universe Packages

How should I edit my /etc/apt/sources.list so that I can proplery 
maintain a current version of R, and not break my system? I've searched 
the forums at Ubuntu, and there are several similar requests there, but 
no definitive answer that I found.

What are other Ubuntu users here doing to keep their version of R fresh?

Thanks,
Clint

Clint Harshaw, PhD               Email: charshaw at presby.edu
Department of Mathematics        Ph: 864.833.8995
Presbyterian College             Fax: 864.938.3769	
Clinton, SC USA  29325           Harrington-Peachtree Rm 412