OS X in a VM?
It's easy if you are willing to bear the bugs: No version of VMware tools will run - sluggy mouse and video. You won't get the virtual NIC device to work, neither as sound or usb. To exchange data with the VM, you will need to attach a vmdk (virtual harddisk) containing those data.
Else:
http://pcwizcomputer.com/index.php?option=com_content&task=view&id=76&Itemid=48
p.s.: This won't run on ESX, which is quite a pity. I've tried on Workstation and it works as supposed.