I've always assumed that this is something inborn instead of learned -- hopefully, that assumption (which come to think of it I've never really questioned) is wrong -- but I have a very hard time orienting myself. When I'm walking up the stairwell in my apartment, I have no idea whether I am walking towards the road, away from the road, or perpendicular to it. I can sit down with a pencil and paper and draw it and figure it out by looking at it from a 'birds eye' perspective. But when I'm standing in a room with opaque walls and trying to imagine what room is on the other side, I just get really confused.

How do you speak clearly?

I have a bad speaking voice -- my sibilants ("S" sounds) come out mushy. If I record my speaking voice and play it back, even when I'm concentrating on enunciation, I sound... terrible. It's a voice that sounds geeky at best, retarded at worst. A little too high-pitched and monotone, as well. People have been telling me they can't understand what I'm saying all my life.

It's quite likely that I'll give many public presentations throughout my life, so being better at speaking might be worthwhile. I've lost my fear of public speaking (knowing the material well takes care of that) -- I'm just talking about the mechanics of speech. I want to be audible, comprehensible, and not sound like a moron.