Do you imagine an appearance for Omega? A voice?
It isn't a definite image, but it is a rather big robot (10m high or so) with a not so big spaceship (both metallic and predominantly silver), with transparent boxes full of dollar bills. It has a normal male voice, probably cultivated, like an actor or TV star. I have not decided which language Omega speaks. Strangely enough, although the appearance of Omega can vary, I always imagine meeting him on two places not far from each other: first one, second one. In the first spot, Omega is physically bigger and presents the traditional Newcomb scenario or its variations. In the second one, there is a more advanced and smaller version of Omega (it's a rather narrow street, after all) engaging in counterfactual mugging and that stuff.
I find Omega so profoundly annoying that I don't bother with problems that include it. I know, it's just a philosophical tool, but between not believing that such a thing is possible, and believing that if such a thing were possible, I couldn't recognize it, Omega just has a tremendous ugh field. If I start thinking about it a little more, I get distracted (though less intensely-- this isn't a deal-killer) by questions of motivation. If I had that much power and knowledge, I wouldn't spend my time nagging people with brain teasers.
In any case, many people on LW do think about problems including Omega. Do you imagine an appearance for Omega? A voice?