I think the key is exposure to sunlight to reset your body clock and circadian rhythm. If you get in early, get as much sunlight as you can; if you get in late, minimize your light exposure. I seem to remember somewhere that fasting might also help you get on track more quickly, something about the body and how it responds to food. If you're in to taking stuff, people talk about melatonin, though I have no personal experience with it. And +1 to what moonwilson said about following the local schedule immediately (in line with the sun exposure thing).
ETA: Have to mention that I haven't really seen any good data on any of this though.