I hock loogies. I can spit pretty far too.
Same here! If I swallow too much I get nauseous. Spitting it out is the most environmentally friendly way to do it. It is a natural function to excrete such things. I don't understand why people get so bothered by it. I only spit in the grass/plants or the street where people are less likely to encounter it, as a courtesy to society. I spit constantly while I'm driving. I've been attacked several times over the years for spitting on other cars accidentally and they chased me down, all pissed off. 
Some cultures feel that spitting is the utmost insult anyone can show to another person or to the very face of nature itself. I am not one of them, but as natural as some bodily functions seem to be to some of us, there are other people who see certain bodily functions as more spiritual than functional and those people may be quite easy to insult with even the slightest reference to what they hold as Reserved-For-The-Holy-Ones. Those bodily functions must be pursued only within the spiritual presence and with the blessing of the Holy.
Spitting is serious shit!! I have seen fights begin over a simple bit of misrendered spittle.
While I understand other cultures have their beliefs, I do not understand the logic that I am responsible for meeting another culture's beliefs whether I am in that culture or not. That seems to place one set of ideals above another, which doesn't respect the other beliefs. I'll respect people to live their lives their way, but demand the same in return. Otherwise they can fuck off.
With regards to accidentally spitting on your property, I agree and understand that being upsetting to people, as it is a violation of one's personal space/property. However, chasing someone down and attacking them violently is extremely immature and barbaric. If I did it on purpose, as in we were having words and I spit on you or somethign of yours, then whatever. I still don't believe in violence. but that can be a form of assault. The response should be of equal measure, but we know that is not the case.
To make my point clear, I do take into account my surroundings and the potential interaction of other people with my excretions, but I cannot always properly compensate for wind and other forces of nature.
Oh yeah, as an abomination to nature itself...I say whatever! Seriously, our excretions are nutritious for most other life forms, so sharing them is actually good for the environment. Maybe sans the methane gas.
... and our very breath, to hear some WACKOs talk about it, but I'm a horticulturist at heart (though somewhat frustrated, right now).
Don't worry, I would NOT chase anyone down. I was mainly joking around and pointing out one of the curious ways other people's superstitions can cause them to behave.
Here's an idea ...
"Your right to drive your car ends where ever my spit goes. Deal with it!"
On a similar note, I have had people drive around the block, stop on the street, get out of their car to interrupt me from mowing my grass to tell me that a rock flew up from my mower and hit their car. They then asked me something like what I was going to do about it. BASTARDS!
My response is usually along the lines of ... "Help me to try and understand this. You saw that someone was mowing their grass, creating a dangerous situation for you to drive through and you chose to continue driving down that street, knowing full well that dangerous work was happening there, yet somehow you expect ME to be responsible for your poor choice?"
To begin with, I don't have any fucking rocks in my lawn. It may be possible that a small pebble from the road landed there and my next mowing tossed it back out towards the street, but it would not be anything big enough to even scratch paint.
I honestly think that some people just want to be dickheads, sometimes.
