Rounding column in attribute table using ArcGIS Field Calculator?

Have you tried something like what's below in the Field Calculator?

round(!FieldName!, 2)

Make sure you set the Parser to Python in the Field Calculator.

When you go to dispay, calculate or label the field you could just use,
round ([my_field],2)
also to change the field behavior in arcmap...

Sounds like some simple string formatting would do the trick for you:

>>> "%.2f" % 3.99999
'4.00'
>>>

or, with the number stored in a variable:

>>> j = 3.999999
>>> "%.2f" % j
'4.00'
>>>

This could easily be wrapped up in a Field Calculator function.