I also tried the CentOS 5.5 LiveCD and had it hang at boot. Instead, I pre-installed Fedora 14 LiveCD (from usb installer). I extracted vmlinuz and initrd.img from the CentOS 5.5 DVD, placing them in root. Then I modified the grub loader (/boot/grub/menu.lst) by adding an entry for CentOS, as per the CentOS wiki:
First, change the timeout to 5 from 0 to allow you to select your OS. Then add the following lines:
title CentOS 5.5 Install
root hd(0,0)
kernel vmlinuz
initrd initrd.img
Since Fedora runs on ext4-formatted HD, but anaconda won't read from an ext4 HD, I put the CentOS-5.5-i386-bin-DVD.iso on a FAT32-formatted usb stick (at least 4GB). I then booted, selecting the CentOS install and pointing the loader to the usb drive (sdb1). The OS installed easily from there.
In 3 days, a completely turned off laptop discharges by 6%