Iam use Centos 5.4 PAE minimal install but with X Windows System on first instalation
Install the Gitco repository
# cd /etc/yum.repos.d/
# wget http://www.gitco.de/repo/GITCO-XEN3.4.1_x86_64.repo
#yum -y update
# yum groupinstall Virtualization
dont forget to change default boot on /boot/grub/menu.lst
#reboot
for detail instalation email me :D