IsNullOrEmpty

/// <summary>
/// Determines whether a collection is null or has no elements without having to enumerate the entire collection to get a count.  Uses LINQ.
/// </summary>
/// <typeparam name="T">The item type.</typeparam>
/// <param name="items">The items.</param>
/// <returns>
/// <c>true</c> if the collection is null or has no elements; otherwise, <c>false</c>.
/// </returns>
public static bool IsNullOrEmpty<T>(this IEnumerable<T> items)
{
    return items == null || !items.Any();
}

var list = new List<string>();
list.Add("Test1");
list.Add("Test2");
Assert.IsFalse(list.IsNullOrEmpty());
list.Clear();
Assert.IsTrue(list.IsNullOrEmpty());
list = null;
Assert.IsTrue(list.IsNullOrEmpty());