An enterprising OQO user has gotten Leopard running on his tiny PC. If you aren't familiar with the OQO, it is billed as 'a full PC that fits in your pocket.' It has a slide out keyboard and runs a full version of Windows, and not Windows Mobile.
According to trf's forum posting Leopard is running pretty well except that video resolution is stuck at 800x480 and the WWAN card isn't working yet. Check out this YouTube video to watch the OQO boot up (it takes about 2 minutes to fully boot). Leopard seems to be running fairly well on the OQO, but don't whip out your wallet just yet. As with all non-Apple hardware that is running OS X, this isn't supported by Apple.