You probably already stocked up on stuff--but my preference is Airborne--it has tons of C, B vitamins, zinc, echinacea-- all that good natural stuff that if you take it early enough can help prevent getting sick or if you already have a cold can shorten the duration. I am also a big fan of goldenseal/echinacea combos. But if you are looking to lesson symptoms and save fellow passengers on a flight, I agree with alka seltzer cold. And of course when you get to JA--overproof with fresh lime juice, warm water and honey--and if you can stomach it--some chopped garlic thrown in. A rasta friend cured me that way once when I lost my voice due to a cold. Or maybe I just got a buzz on and didn't feel the cold anymore.