When Im calling from my iPhone to any other phone if that person is on a call Im not shown as call waiting

That has nothing to do with you. Call waiting is a carrier feature and must be enabled at the carrier, and then on the phone. How the phone handles it depends on how the carrier handles it in the carrier file, but it is a problem for the person you are calling, not you.

You know that because you can see that person's phone, or from what they tell you? No chance whatsever that they didn't want to take your call - right?

Do you mean that the person you're calling doesn't know that you're calling? Or do you mean you don't get an indicator on you're end that the person you're calling is on a call? If the former, the person you're calling will need to contact their carrier and sort out call waiting. If the latter, that's not a feature of the iPhone. I've heard it exists on some Nokia's but have never seen it myself.