[CentOS] Installing from working Linux partition

I've got some servers running other flavors of Linux (eg. FC2) and I'm 
wondering if I can install CentOS5 to a new empty partition (eg. on a new 
drive) while running under the old OS?

It seems like the installer OS just needs some hardware sniffing ability 
and the ability to read the installation media and write to the target 
media, so in principle one should be able to install from a working system 
to the new partition and then update one's existing GRUB config. Is this 
doable or perhaps even commonly done?