My friend bought a new PS3 and he already installed Ubuntu GNU/Linux onto it (http://psubuntu.com/). When he asked me over to them to see his new PS3, I noticed afterwards that the PS3 is utilizing a PowerPC processor (Ok, you may know that, but I didn't)..
So I told him to wait a minute, I went to my house and looked for my Mac OS X Tiger installation DVD's for the PowerPC. We tried to install Mac OS X through the Install OtherOS in the XMB, but the installation failed many times. So my friend installed Ubuntu GNU/Linux again into his PS3, and then I remembered a PowerPC Mac emulator for PowerPC processors, namely Mac-on-Linux (http://mac-on-linux.sourceforge.net/).
After we installed Mac-on-Linux, we tried to install Mac OS X Tiger from my installation DVD's, and it actually WORKED! So we fired up Mac OS X Tiger and installed PureBasic 3.94 for Mac and it works flawlessly (PureBasic 4.00 Alpha for Mac made the Mac emulator crash)..
Sadly we don't have any camcorder or good camera to take pictures/videos of this cool thing and although the environment was pretty slow, I proved that Mac OS X and PureBasic work on the PS3.
Really nice, isn't it

PS: For the record, I tried the same using the Intel-version of Mac OS X and QEMU, but it was very slow to boot and then made the PS3 reboot.