Do you know the website Foodily?
You can use it to compare the nutritional content of different versions of a recipe. It's especially helpful if you cook for people with dietary (or gustatory!) constraints. Here's how it works:
Say you want to make tomato soup for a dinner party. And you want it to be low-fat and low carb. And one of the guests is allergic to dairy. You just input "tomato soup" and check the appropriate filters. In seconds, Moodily serves up a bunch of recipes that meet your criteria. The recipes are displayed in a side-by-side format (often with images), so it's ridiculously easy to compare ingredients and nutritional data, and determine which recipe is right for you.
One downside for me is how the nutritional content is calculated. It's calculated per recipe rather than per serving. That makes the site less helpful for calculating insulin dosages. (You can read here why Foodily doesn't generate per-serving data.) Even despite that shortcoming, I like the site a lot.
Thanks to Foodily, I'll be making this tomato soup tomorrow night.