This resource is awesome...and it's by the USDA?!

I haven't looked at it in depth but from what I have seen, I am impressed.

You can quickly view which foods are the highest in your selected nutrient.

So magnesium - buckwheat flour! Never woulda thought.

Check out the USDA National Nutrient Database

Related to that site is this resource:
Food & Nutrition Information Center

Bookmark them....and my blog! :)