It's now pretty simple, all you need is a Gigabyte Mainboard with internal USB and this nice little USB tool that costs over here 169 Euro:
http://www.efi-x.com/index.php?language=english
EFi- X? USB V1
Revolutionise your digital lifestyle easily and securely.
BPU on USB internal 10-1 pins. (with extended size)
Online updates of EFI-X? firmware.
Interactive system boot selector.
Install your favourite OS from original retail DVD.
Update your system with official unmodified updates.
ESD and EMI protection.
No need to modify any files, just put in OS X DVD and go for it
