My wife carries bubble lined SASEs with her when she flies so that if they won't let her fly with something, she puts it in an envelope and they mail it for her. Had to use this twice now--once for a bottle of perfum, and once for a pair of small solingen surgical scissors.

I on the other hand, flew with a pint of Stoli poured into a Pedialite bottle (re-sealed) tinted with orange Kool Aid and sailed through like a champ flying with my 2 yo last week