Everybody else
You are a complete stranger, I will do my best not to get in your way.
Mostly Stranger
This is when I know of you - your name, and potentially some of your traits and skills. I will acknowledge your presence, but will likely still avoid you.
Simple Friend
I have interacted with you enough and I like/respect you. Will say "hi".
Regular Friend
I am comfortable enough around you to speak my mind.
Good Friend
I will go out of my way to help you - you can break my schedule.
Close Friend
I may share secrets with you. You can change my routine.
I dislike having a lot of simple/regular friends - I'd like you to be at least a good friend, or not a friend at all - I don't like half efforts, so if you're a simple friend, I'd like us to either keep growing our friendship until it's solid, or we shouldn't have started in the first place.
To move up in the levels of friendship, typically you'd have to be present in my life in my daily routine - the quickest friendships to build are the ones with the people within proximity; I will not go far out of my way for a stranger to turn them into a friend - there are enough people around me to grow and maintain friendships.
