The only way I could thing you could do is to make a formula to first do a date difference of the date part, then do a date difference on the time part and concate them together (convert to text first).

Well this seems to work pretty well, of course it there is an issue with getting negative numbers in the time portion.  I would have to do further research to get the time value converted to a number as a whole then do the subtraction.

numbervar hourdiff := hour({datetime2})-hour({datetime1});
numbervar daydiff := date({datetime2}) - date({datetime1});
numbervar minutediff := minute({datetime2}) - minute({datetime1});
numbervar seconddiff := second({datetime2}) - second({datetime1});


totext(daydiff)+" "+totext(hourdiff)+":"+totext(minutediff)+":"+totext(seconddiff) 

Can you define this more clearly? You state you want this in Month Day Hour Minutes, but how are you defining a month?
Your example "i.e.  11/18/09 03:54:00 - 11/19/09 05:00:00 = 1 01:06:00" is easy to understand but what about something like...

Edited by DBlank - 25 Nov 2009 at 9:53am

Create 3 running totals to do a count on ({Order.OrderID}).