Site: http://www.healthassist.net/food/300kcal/300.shtml

How do you develop a sense for how many calories you are eating? By seeing pictures of food portions and how many calories are in those portions. Eventually you just kind of absorb the numbers and though you may need completely accurate, just having a feel for how much you are eating is good enough. That's why a love sites like this 300 Calorie Food Picture Gallery. You'll see a picture of apples and see that two apples are about 300 calories. This site even estimates the cost for a 300 calorie portion. There are even instruction on how to create your own picture gallery. Very cool!