There are also vibrators with built-in travel settings now, to prevent them from going off at an inopportune moment, like the Surge silicone rechargeable vibrator, which has a built-in travel lock.

What’s the liquid rule again?

“The most common mistake that we see people making in terms of prohibited items at airports are large liquids, gels and aerosols in carry-on bags,” said Lisa Farbstein, a spokeswoman for the T.S.A.

T.S.A.’s widely publicized 3-1-1 rule dictates that passengers may travel with liquids, gels and aerosols as long as they’re in 3.4-ounce containers in one quart-size resealable bag. So while a bottle of water won’t make it through a preflight screening, what about something in a more nebulous category, like a jar of peanut butter?

“If you can spill it, spread it, spray it, pump it or pour it,” Ms. Farbstein said, “it is a liquid, gel or aerosol.”

This is why a Magic 8 Ball, which is filled with liquid, is not allowed through a T.S.A. checkpoint. The same goes for a snow globe. Unless, of course, as Ms. Farbstein points out, either is a version that’s small enough to fit inside a traveler’s 3-1-1 bag.