Melantonin. The FA's use it. Take it when you want to sleep on the plane. Don't take it for more than a day or two or you will be druggy. Never nap upon arrival - kills you for a week.

My best cure for jet lag was arriving Munich just in time for a big night at Octoberfest. Drank copious quantities of beer, got to bed about midnight. Slept REALLY well. No jet lag at all!