IEnumerable Each()
I've wanted to write an each statement for IEnumerable for a while, but haven't bothered, mostly because other devs had decided to translate everything to List anyway so I just used .ForEach or a straight foreach as appropriate. A comment on my Avoiding FizzBuzz post by Matt Taylor spurred me to do an implementation.
Anyway, an Each() extension method on IEnumerable is trivial:
public static class IEnumerableExtensionMethods
{
    public static void Each<T>(
        this IEnumerable<T> list
      , Action<T> action)
    {
        foreach (var item in list)
            action(item);
    }
}