When I went on a 14 hour flight, I managed not to even use all of my iPod's battery power during the flight (8 hour battery). I recommend that you do something else for the first few hours, possibly listen to music a little bit. Then, when you should sleep in Russia, go to sleep! After that, watch some movies or listen. Between all of that, you should stay pretty happy. Those flights are really long, but if you break it up into "activities," you should be fine. Oh, btw, I don't know if this works on other iPods (I've only been able to do it on my 3G 40GB), but if you restart the iPod and enter its testing mode, click on the option B. RESET. If your iPod is totally out of battery power, it'll reset, and you'll end up with a couple more hours of power (I got two more hours after the iPod shut itself off because of lack of power). Have fun!
-Chase