I like to keep track of my tomatoes and my diet, so I use one of these attractive and relatively inexpensive kitchen scales which use piezo-electric crystal stress sensors to make their determination of weight. I'm really impressed with them since the two I have are so reliable and consistent. You can take the thing you are weighing off and on and it always reads the same which is one of the marks of a good measurement system.
I use the scales to weigh both tomatoes and food. I'm on a diet that is really fairly simple — shift food intake from 100 calorie per ounce food to 5 calorie per ounce food and eat all you want. I've dropped 45 pounds since May which isn't too bad. I started at 272 and I was 227 this morning. My long term goal is 170 so I still have a long way to go. If anyone is interested I'll say more.
The tomato is a perfect fit into this diet since tomatoes are nominally five calories per ounce. I let the food consumption range up to about 20 calories per ounce (grapes) before I get a little stingy with myself. You need a handy little digital scale if you're going to do this kind of diet since you have to measure how much things weigh or guess, but measuring is better.
I exchanged links with Joseph Wright at www.digitalkitchenscale.org so you'd have an easy link to go look at these interesting little scales. The growing season is about done and now it's into the eating of the last red ones and the waiting for the green ones to turn read or enter the fried green tomatoes experiment.