In June, Mat wrote about the EFi-X, the internal USB-dongle that claims to allow a user to install OS X from a retail disc onto a non-Apple PC. Essentially the EFi-X is a mod-chip for certain Intel motherboards that will trick the Apple Retail discs into thinking that the hardware is Apple-sanctioned.
http://www.tuaw.com/2008/06/14/efix-usb-dongle-for-installing-os-x-on-a-regular-pc/