So it's not Windows, but some Mac ninjas have figured out how to book Gentoo Linux on a 17-inch iMac Core Duo. No specs yet, but check the page for their patches and instructions. Now if they could get VMS to boot on there...

Using elilo and a modified Linux kernel, we can boot from a USB hard disk on the 17" iMac Core Duo. We are using the hacked vesafb driver to inherit the bootloader's framebuffer, keyboard and a USB network card work. Gentoo runs and can compile the Linux kernel. Look closely at the second screenshot and you can see that it's i686. :-)

Wiki [Xbox-Linux]