yes - I have found several soul mates as well. I used to say that I don't believe in soul mates, because my definition of love is not all butterflies and NRE... I think of it as decisions, choice, and action.
My best friend is my soul mate. We know we are to each other. She is female, the relationship is platonic. I have known her for 20 years and although we have lived 3000 miles away from each other for most of that time, we are emotionally inseparable. We both feel very lucky to have each other. If I ever want to have a child, she would be my surrogate.
My father is also a soul mate. We are best friends and understand each other on a very deep level.
There are others too... So, I guess I would base it on several things - circumstance- for one, timing, a connection stronger than distance or time... Ease of communication, understanding, and love. Unfortunately my husband was not one of them...
However, I am one of the fortunate people to have many, many very close friends. There are several out there that I would die for... completely genuine and loving people that would do the same for me. The fact that this is not so common is one of the things that got me thinking about polyamory, in fact.
Thanks Vandalin for bringing this topic up. Thinking about these friends makes me feel very warm and loved.