What actually causes the "stitch" you feel in your side while jogging?

So, I'm a runner...
Actually, no. I'm not. But I am going to begin telling myself that I am, so that hopefully my subconscious mind will begin to believe that:
1.) I am enjoying this torture.
2.) I can actually continue it on a regular basis.
3.) I will eventually be able to run a full lap up and down my street without wanting to just lie down in someone's yard and rest.
So far, it's only barely working. I ran (by the way, I'm using this word VERY loosely) three times this week, which I count to be a great success. I've never been much of a, um...hmmmm...how can I say it...let's see...a, um, person who likes to move very much. At all. I pretty much dislike any activity that is more rigorous than walking, say, from my car into the mall. Or from my cubicle to the printer. Actually, no, strike that. I dislike that walk too. How 'bout...from my couch to the refrigerator?!
It's not that I'm a fat, lazy slob. I've just never really been one of those people who's HAD to work out to keep from blowing up like a blimp. Until now. I am facing the fact that, with the big 3-0 looming on the horizon (the VERY near horizon), I'm going to have to do more than watch what I eat if I want to stay thin.
But so far I can already see that this is going to be tough. Being a beginner, and also extremely unconditioned, I'm no stranger to the piercing pain in my side when I exert myself beyond what's comfortable for me. But today, as I made my last (third) agonizing lap around my cul-de-sac, it was almost unbearable! It felt like someone had jammed that fireplace poker thing with the crazy hook on it into my abdomen...AND TWISTED IT!
So I thought I would look into exactly what causes this...so as to never experience that feeling ever again. I thought this knowledge should come in handy. You know, since I'm a runner now.
The general consensus seems to be that the pain is caused by visceral ligaments (those that support and connect the internal organs) that stretch as a result of all the vertical force and jolting you cause while running (or working out in really any capacity). Since the liver is the largest organ in the abdominal cavity, the pain is most often felt in the right side. As gravity causes the liver to pull down on these ligaments (which hold the liver in place below the diaphragm), the diaphragm is also lifting UP as we take frequent, short breaths.
There are various recommendations as to what you can do to prevent or alleviate this pain. Take deeper and less frequent breaths. (Who are they kidding?) Wait 2-3 hours after eating or drinking before exercising. (Too bad I'm a grazer.) Drink water beforehand. (Wait a minute. I thought you just said...never mind.) Exhale when your left foot hits the ground, instead of your right. (No way can I concentrate that much while running.) Press your hand just below the location of the pain to give the organs a "lift." (Creepy.) Run on soft surfaces. (Good thinking. I'll cover my street in cotton balls before my next jog.) Improve fitness. (Overnight? Yes. Brilliant!)
Although I think they may be on to something with that last one. I'm holding out hope that...as I continue "running"...my endurance will improve, I'll breathe slower, I'll sweat less, cramp less, swear less, etc. I just hope it's soon! Otherwise, I might have to buy myself some new running attire to keep me motivated. So until my optimum level of fitness is reached:
Q: What actually causes the "stitch" you feel in your side while jogging?
A: Being miserably out of shape!