[CentOS] centos 5.2 booting thumbdrive

Anyone have instructions or have been successful in booting centos 5.2 
from an thumbdrive?

I have instructions for centos 4 from 
http://fungliding.blogspot.com/2005_04_01_fungliding_archive.html
and that worked. However, it doesnt seem to be working for centos 5.2.

Thanks for any tips.

Jerry