This is what you do. Water bottle technique basically. Get the water that comes in a large pack from a wal-mart/Safeway (the smaller ones that are made of that thinner plastic) cause they have shittier lids. Simply dip the caps into boiling water at home. That should soften the plastic and make it easier to take off without busting the seal. The cap should be fairly easy to put back on even after it cools down.
Also. I like to throw several normal waters around it in my bag when going through security
I still don't get why Modest Mouse is headlining and I am a pretty big fan. Hopefully the Lips pull a Pavement and play significantly longer than their allotted time slot, but I doubt that. Last time I saw them, Wayne Coyne said they couldn't play more cause "the whales needed to sleep.
I hope they give them enough time to play more than the Soft Bulletin. As good as that album is, a Flaming Lips concert wouldn't seem complete to me without Yoshimi, the WAND, She Don't Use Jelly, and Do You Realize.