There are quite good instructions in a blog post I found http://blog.dakdad.com/post/13145939686/install-wkhtmltopdf-centos-5 - the version available in the repo is 0.9.9. If you are cool with that that option will work.
Edit: Because I'm a huge nerd I tested using a Virtual CentOS box and using the method above worked. I also wanted to test the static binary option too and got that way working too. The basic steps (I did them as root, it should work even without root access - depends a lot on your server):
# If you don't have wget installed
yum install wget
# get wkhtmltopdf binary.
# browse the site to get the correct one for you
# if you don't know which one, run the command uname -a
# if it has things like x84_64, get the amd64 one. Otherwise i386.
wget http://wkhtmltopdf.googlecode.com/files/wkhtmltopdf-0.11.0_rc1-static-amd64.tar.bz2
# unpackage binary
bunzip2 wkhtmltopdf-0.11.0_rc1-static-amd64.tar.bz2
# untar
tar xvz wkhtmltopdf-0.11.0_rc1-static-amd64.tar
# make sure you have the file, the file list should contain wkhtmltopdf-amd64
ls
# run to check version, output should contain "wkhtmltopdf" 0.11.0 rc1
./wkhtmltopdf-amd64 -V
There you have your very own static package. I tested it with
./wkhtmltopdf-amd64 http://www.google.cn googl.pdf
It worked! The chinese characters fail because I don't have anything else installed on the CentOS box, I would propably need fonts and whatnot but the PDF was indeed created and looked ok.
Good luck, have fun.