How do I round down a decimal to two decimal places in .NET?

Is there a built-in method for it? The .NET framework must have a method to do this!

private decimal RoundDownTo2DecimalPlaces(decimal input)
{
   if (input < 0)
   {
      throw new Exception("not tested with negative numbers");
   }

   // There must be a better way!
   return Math.Truncate(input * 100) / 100;
}