(Don't blame me for this silliness, XCthulhu asked me to...)

If you have MultiKey mapped to some key, an *NIX spelling would be:

MultiKey-^-o, MultiKey-?-?, MultiKey-^-o = ô¿ô

(You may need to repeat the circumflex if it's used combinatorily).

(OK, this is getting pretty silly. I promise not to participate in anything like this anymore. =)