We have a cluster. We are recommended to use cluster nodes instead of the portal computer to do any computation or anything above light work (i.e. text editing). I recently wanted to view pdf files (output from an analysis) on a node. Some of these can be big files, and so I don’t want to do that on our portal computer.
I downloaded the linux xpdf binary from (http://www.foolabs.com/xpdf/download.html, under pre-compiled binaries), untarred it, then installed it into a subdirectory of my home directory (we do not have root access or access to /usr/* or /opt/* so I installed it to ~/programs/xpdfbin-linux-3.03/. Then editing my ~/.bash_profile, I added
PATH=$PATH:~/programs/xpdfbin-linux-3.03/bin32/
and had the ability to do
xpdf mypdf.pdf
to view a pdf on a cluster node! NOTE – some systems may fail using the bin64 case, as did our cluster.
ALSO – now I can view R Vignettes directly on the cluster instead of toggling back to local.
Hope that helps.
A HopStat and Jump Away 
It’s great that you got this to work. But when I tested it, even opening a short R vignette takes a long time. Am I doing something wrong or is this a shortcoming with this approach? If it’s the second, I think that I will stick to copying the pdf to my computer and then opening it locally.
So it sometimes takes a while – but it obviously has to transfer the data to your computer, just the same if it were a plot. Thus, if it is a large vignette, this may take a while, so would depend on connection. I did not want to continually copy locally to view results or installing packages locally to view vignettes. I tend to simply google for vignettes anyway vs. either approach.