I've done it on an old Mac Mini but the amount of farting about with rEFIt ( http://refit.sourceforge.net/ ) and keeping a partition for OS X just in case the machine's firmware needs an update, and fiddling to get the sound to work, means that I wouldn't do it again.
It works properly, and doesn't need any special treatment once it's set up, but the OS X-specific firmware makes installing anything but OS X a misery.
I've done it on an old Mac Mini but the amount of farting about with rEFIt ( http://refit.sourceforge.net/ ) and keeping a partition for OS X just in case the machine's firmware needs an update, and fiddling to get the sound to work, means that I wouldn't do it again.
It works properly, and doesn't need any special treatment once it's set up, but the OS X-specific firmware makes installing anything but OS X a misery.