Let’s assume that you need a server alive and kicking ASAP (and there is no time to start a recommend-approve-purchase process). So what do you do? You build the server from spare parts found here and there. After one or two hours you come up with a server that has two SATA disks setup as a RAID-1 array on a PCI controller.
Only there is a problem: You cannot boot from the PCI SATA RAID controller. And there is no real need to sacrifice an IDE disk just to boot the server. Now what can one do?
One simple solution is to use an IDE to Compact Flash adapter:
That way a compact flash card can be used as a /boot filesystem. With only a minimal cost (~11 Euro in my case) and a (spare) 128MB CF card you can have a /boot on the (on-board) IDE controller.
Note that CFs are not optimized for multiple writes. In fact, after multiple writes they get …destroyed. So when you are happy with your /boot, back it up on an image file (via dd for example) because one day you may find your server unable to boot. Simply dd the image to a new CF card, replace the old one and boot again.
(The above information is more or less Linux and PC-centric but hey, you get the picture)
Managing organized complexity 
Cute hack I would remark.
I would like to add that hard disks tend to present bad clusters on their very first sectors, where the boot loader and the /boot usually reside.
I had such a disk and wanted to install a minimal linux distribution in order to use it as a router. I used my cd-rom for the boot loader and the kernel image and all my partitions were 1gb from sector 0. It works for more than 3 years without any problems :-)