Some good points on the psychology of food and eating here - chances are you have known this, subliminally, all along.
Just a few observations - if you present a big meal on a huge plate, it will look smaller and you'll tend to eat more to compensate. Better to sneak a smaller meal onto a small plate, your brain will make the "plate 90% full = huge meal" connection even when it *knows* the plate is smaller.
Eating while using a computer is a nasty habit anyway - and you do tend to munch more when distractedly reading your RSS feeds, so don't do it. Have snacks between meals, by all means. Just not while at the computer. And if you have snacks, try and skip a meal. Have a good breakfast, snack during the day, and skip lunch.
Are you the cook? Get a smaller set of saucepans, and when you read a recipe, mentally cut the fat in half and use body friendlier fats. Trust me, all these things work. Smaller serving sizes are great, but smaller serving vessels are even better. If there's less to go around, most people instinctively take a smaller serving on their plate. And if the plate is smaller too, they may end up eating a meal only two thirds of what they'd serve themselves if the serving vessel was huge.
Your brain is finely-honed and superbly tuned, just not for instances like this where old survival traits (like stuffing yourself at mealtimes) meet modern social requirements. (Like not becoming overweight, not taking the last serving, not appearing to be the "greedy" one.)
Unfortunately, when it has instances like this, your mind hands over to the old atavistic brain and that's why we need to fool it. So even if it sounds like utter crap to you, give it a go and be surprised.