It looks like a guy over at OQO Talk has “modified” his OQO so that it runs MacOS Leopard.
Bluetooth works, WiFi works, sound and power management all work, and for the skeptics out there there is even video posted (after the jump).
“The Leopard install is legitimate and works quite well. However, I am still working on two final issues which are video resolution, presently limited to 800×480, and wwan which I have not yet attempted. Sound, wifi, power management, and usb are working fine and the system is very responsive. When I have completed these final tasks I will post a review with further details.”