That is until now; a company called Art Studios Entertainment has created a Boot Processing Unit (BPU) called the EFi-X USB V1. This device attaches onto an internal USB header on the PC's motherboard.

It works by running a version of EFI that lets OS X function on the PC architecture. The EFi- X is composed of an embedded CPU with several gigs of onboard memory, and a USB connector. It features its own firmware, which is constantly being upgraded by the creators to improve features and address any discovered hardware issues. "

Review Link: http://www.testfreaks.com/blog/review/efi-x-usb-v1-reviewed/