In response to redsoxfan, I would say yes! My logbook final column says "Total duration of Flight". It does not say total pilot flight time or total time.
If you operate as a flight engineer from point a to b and it took 1 hour, I don't see anything wrong with entering 1 hour in the total duration of flight column. The other columns should explain what type of flying and seat position, etc.
In addition, the FAR's require a flight engineer to log 50 hours of flight time as a flight engineer within the past 6 months to maintain currency. What better place to do this than the Total duration of Flight column.
Also, FAR 61.159 (c) states that "A commercial pilot may credit the following second in command flight time or flight-engineer flight time toward the 1500 hours of total time as a pilot required by paragraph (a) of this section

iv)Does not exceed more than 1 hour for 3 hours of flight engineer flight time for a total credited time of no more than 500 hours."
According to the above regulation, If a flight engineer is a commercial pilot, then it is considered flight time. Since logbooks don't have a column for flight engineer flight time than the total duration of flight column should suffice.
Hell, the logbook's purpose is to record minimum currency requirements. After all, a logbook is nothing more than a "book in which details of a trip made by a vessel or aircraft are recorded." (Random House, 2000)
As far as using it on a resume use your best judgement