Eye Contact - a fine line between confident and creepy

I'm a floor starer - its true. When i walk down the hall I usually look at a spot that is rouhgly five feet in front of me and on the ground. I don't think that I have self-confidence issues. I just never know how to look at people as you approach them. What is the exact level of eye contact one should have?

If you have too little you come across as weak or arrogant depending on how you look and how hunched over you are. If you look too much, you either come across as trying to intimidate the men or a creep to women. Or vice-versa if you're a woman you come across to men as forward. So, it seems to me that there is a formula that has all the right ingredients. Eye contact for just the right amount of time, not too soon as to create uncomfortable moments, but not too late as to cause a startling moment in the eye-contactee.

Where I work, there is a very long hallway where you might see a person coming at you for at least 75 yards. At the begining you know there is very little chance that they might break left or right to go down the cubicle pergatory where engineering is located. So, then you start to worry, should I look now? or should I wait. if its one of my bosses, I've seen them all day, yet I know I should acknowledge them. So, I've developed this plan. 75 yards out I size up my quarry - Is it that woman who always looked flushed who is way too happy to see me? Is it that guy who seems to hate me for some reason? Is it the crazy janitor who always wants to talk about sports? Once I've decided who the person is, and if they are eye contact/head nod friendly, I then plan out my attack. If we have the same gate and will meet in the middle, I will look at the floor for another 15 yars. At five yards, I will act as though i notice them, and will smile gently but not too excitedly while I questionly attempt to make eye contact. If they take the bate, I lock in and give a very confident, yet masculine nod, as to say, I mutually respect you. if they return the gesture I know we're good. If not, I know that next time, I will continue to look at the floor at the 15 yard mark and act as though I'm calculating a figure in my head (even though I'm an attorney and we all know they can't add).

Over the years I've made a number of head nod friends doing this. I have no idea who they are or what area they are from, but in a week and a half it won't matter anyway. I'll have to find new head nod friends, and create a new template based on the new federal hallway length.