USDA - CNPP - MyPyramid Tracker
I used this successfully for weight reduction. It's a pain at first to figure out how to enter what you eat, but once you find the particular food you can store it in a list and pick from the list.
You can also enter physical activity (same problem and solution) and then tell if you're out of balance because it calculates (really just estimates) calories in and out.
I could only stand to do it for a couple months but that was enough to get me going, and then if I start gaining weight and didn't know why, I'd start it up again for a week or two. I haven't had to do that lately, though. It's a real education on how many calories are in what.
Two drawbacks. One, it tells you to eat lots of grains (the official gubmint food pyramid) but you can ignore that. Two, for me it told me I could eat more calories than I really can. For DH, it was the opposite. But within a week that's all sorted.
Best of all, the price is right. It's free.