You can hot swap PCI/IDE/SCSI devices even on non hot swap able mobo, and doing so is risking your hardware. I have hot swaped solid state dims disk-on-chip, bios, pci vid cards, pci/isa sounds, pci/isa network cards, pci/isa modems, IDE/SCSI hdds & floppies.
The thruth is that is doesn't make my dick any longer because I can do so, and it has killed 1 bios & 1 disk-on-chip out of the dozens of experiments that I did.
I have only proven that hot swap can be done on my own machine a few times to prove to my friends that it is possible, however the devices doesn't work or crash the computer & require a cold boot.
The experiments was done at my old job where I build imbedded firewall system. We sometime would rip apart pix & other systems to see what they use for hardware & hack their OS for comparison to our system & to see what the competitions have. Therefore we have lots of parts to play with when we are bored.
Strange thing that I found in my experiment is that unpluging & replug the same IDE HDD on a computer while it is on doesn't crash the system most of the times. However, floppy drives sometime works & sometime don't. And, all other devices require cold boot inorder for the computer to work. Linux & Unix is much more tolerable with IDE devices than Windows, because you can unmount & remount the system during a swap.
On a related note. CISCO hardware is absolutely crap for hardware because they use mostly Celeron & Pentium processors that required heat sink & a moving fan for cooling, however their proprietor OS is pretty good. As for my old company, they use none moving parts with a CPU that draw only 1.2~2W & a beautiful Linux kernel.