Build Your Own PowerPC?

amokk asks: "Let's assume for a second that somebody would want to take the time and effort to build a Personal Computer but base it on a PowerPC architecture. Besides saying 'Buy a Mac' (I already have one) or 'Buy an IBM server', is there any way of acquirng the individual parts and slapping them together? Why you would want to do this isn't up for debate. Rather, this is one of those 'wouldn't it be neat if...' type of experiments."