[CentOS] Converting to Raid1

Tue Nov 30 16:59:21 UTC 2010
Matt <lm7812 at gmail.com>

Have a CentOS 4.x 32 bit server running on a single 500M SATA drive.
What is easiest way to convert too RAID 1 on it?  Anyone have a link?
Would be open to hardware or software just do not want to reinstall
the entire mess.