It's not free but I use calorie king (
www.calorieking.com). They have a web app and a Palm app both. It will track a bunch of value, including carbs and exercise too. I find it a lot easier to use than fitday (which doesn't have a palm app) and it has been easy to find most of the foods I want and simple to add the ones I don't find.
If you find a good, free app let us know!