I get asked time and time again what to do when trying to get through the hell that can be jet-lag... and to be honest I'm yet to come up with something that actually works besides riding the waves, getting into the local time zone and sleep times as quickly as you can, drinking plenty of water and avoiding caffeine after midday.
However when it comes to preventing jet lag, that's a different story. It's also the most effective way to avoiding it in the first place. And one I can help you with.