I am trying to find res.cls! I've been looking for quite a while for res.cls but have not found it.
All signs point to it being in texlive-latex-extra, but as far as I can tell it wasn't provided.
I am in the midst of installing texlive-full just to see what happens, but nonetheless, I would like to know where or if this file is provided.
I know you can get it via CTAN which is where I'm going next if I can't get it from the Ubuntu packages.
The CTAN won't give you the name of the Ubuntu package, which effectively was texlive-latex-extra, because, the package resume has been removed from Ubuntu (from Debian too, and even from TeXLive apparently) since lucid 10.04, as shown here: http://packages.ubuntu.com/search?suite=karmic&searchon=contents&keywords=res.cls
It seems that the package had a license compatibility problem, as explained here: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=510749
