XMBC. The dev crew has announced the very first cross-platform Beta version of XBMC media center for Linux, Mac OS X (Leopard and Tiger), Windows, and Xbox in preparation for the upcoming stable release of XBMC (which is code named Atlantis). A few notable additions to this version include XMBC Live -- a "bootable CD which gives users the opportunity to try XBMC on their computer, without touching their hard drive" -- and initial support for integrating iTunes and iPhoto media into XBMC... for Mac users, anyway. The final release is currently on track for an October launch, and if you'd like that to remain true, we'd recommend giving the beta a whirl and submitting any bugs to the gurus behind the scenes. So, what exactly are you waiting for again?
Read - Atlantis Beta 1
Read - iPhoto / iTunes integration