Gigabyte GA-P35-DS3L mobo
8 GB Patriot DDR2 800 RAM
3 Seagate HD's (OSX, Windows Vista 64, Fedora 9)
NV EVGA 8800GT Graphics card
OS X 10.5.6
Although, you need retail version of OSX. Also, OSX needs to be updated to latest version for graphics card to work properly. All, in all works good. No need for Hackintosh. OSX updates work just as normal Apple Mac. No recompiling kernels, etc,...It just works.
It's not too cheap, but if you have the right hardware and want to run OSX on your custom rig without much hassle you can.
If your current hardware specs are compliant with the EFI-X USB chip, it is a really cheap "Power Mac"