Intercontinental travel is actually much easier than travel within North America, because on a transoceanic flight you have the opportunity to get good and sleep-deprived, so you can re-set your biological clock by the sun at your destination.

I agree that west to east within North America is a whole lot harder than the other way around. If there's any way you can get yourself sleep-deprived before the trip, I think it helps a lot. Melatonin will help me sleep in general, but really, all it is, is a pill containing your body's response to waning light.