Scott Hanselman is at it again with a smarter and possibly evil ToString extension method.  Here is his example usage:

public void MakeSimplePersonFormattedStringWithDoubleFormatted()
{
    Person p = new Person();
    string foo = p.ToString("{Money:C} {LastName}, {ScottName} {BirthDate}");
    Assert.AreEqual("$3.43 Hanselman, {ScottName} 1/22/1974 12:00:00 AM", foo);
}