Pretty cool little resource. Don't put too much stock in the food suggestions or tips they offer, but this is a very handy way to keep track of exactly what you eat during the day and keep yourself from fudging the numbers. Not everything you eat will be on there but a surprising amount of things that you wouldn't expect to find are. Once you have everything on there you can click "analysis" and get your carb/protein/fat ratio in percentages along with a slightly more detailed breakdown underneath.
Here's mine for today (10/9/2008)
For some background, I am 195lb, 5'11 and my maintenance caloric intake is about 2800 per day. On this particular day my only exercise was my 5x5 routine, which I did for about two hours.
If you're anything like me, you'll be surprised at how many extra calories you were taking in that you conveniently forgot about when you added it up in your head.