How To Perform a Bare-Metal Backup On Linux LVM
perlow writes "Using the free System Rescue CD you can perform bare-metal backups and restores of many types of computer systems. In this article, ZDNet columnist Jason Perlow explains the multi-step procedure in detail on an LVM-based system."
http://www.mondorescue.org/
other features for bare-metal backup/restore involves:
Systemimager (dead good, and also good to restoring an image to other machines too). Restores from a cd (or PXE) boot and pulls the necessary data from the server with minimal intervention.
Any virtualisation technology - depends on your definition of 'bare metal', but if you think of it as an easy-to-restore server, then I guess it counts.
r1soft's (paid-for) continuous backup solution. Not tried this, but many webhost type companies have said its the dogs danglies.