Have decimal amount, want to trim to 2 decimal places if present

Have you tried using value = Decimal.Round(value, 2)?

For example:

using System;

class Test
{    
    static void Main()
    {
        decimal d = 1234.5678m;
        Console.WriteLine("Before: {0}", d); // Prints 1234.5678
        d = decimal.Round(d, 2);
        Console.WriteLine("After: {0}", d); // Prints 1234.57
    }
}

Note that this is rounding rather than just trimming (so here it's rounded up)... what exactly do you need? Chances that the Decimal struct supports whatever you need to do. Consult MSDN for more options.

decimal.Truncate(myDecimal * 100) / 100

This would cut away everything following the first two decimal places. For rounding see Jon's answer.

If its just for display purposes, you can use:

Console.Out.WriteLine("Number is: {0:F2}", myDecimalNumber);

I use this: Math.Round(MyDecimalValue,2);