modafinil
Okay, I flogged this in another thread a few months ago so am about to become at risk for being accused of pushing it, but I think it's important to spread the word that 200 mg of modafinil will keep you alert when your brain otherwise would much rather that you sleep. Amazingly if your flight is canceled and you've taken the med, you can still go to bed and get a good night's sleep. You should read wikipedia and talk with your medical advisor of course, but if I were your parent I'd really hope that you had it in your kit.
pj