MunchMaker is a website dedicated to creating grocery lists, and sharing recipes between friends. I made it mostly for my own use, for easier trips to the grocery store, and as a learning exercise.
Here's a screenshot from the grocery list creator:
The idea with this page is that you can click on a recipe to add all its ingredients to the grocery list. If you don't need all the ingredients in the recipe, you can click those away. Another nifty feature is that you can add recipe's created by your friends as well.
Below is an example of a grocery list. The ingredients are sorted by category, which makes it a whole lot easier when you're out shopping (sorry about the Norwegian names by the way).