You already know to give a kid a bottle or pacifier to suck on during takeoff and landing, right? [Actually, after the kid had a near-meltdown before we even left the ground, one flight attendant told me they start pressurizing the cabin as soon as the door closes, and it's good to get a baby drinking/swallowing/sucking right away to ease their ear pressure. But I digress.]
So we're descending into Chicago, and we've started the bottle too early; the kid's going to finish way before we actually touch down.
But since we have those Playtex Ventaire bottles, I just unscrewed the end and poured some more water in and resealed it. It's no MacGyver or anything, but it worked out well. No fuss and no interruptions.