aa in their travel kits (which you get free when you fly business class intl) include a tube of toothpaste, generally 0.6 oz or less; once they included a tube that was 0.2 oz--somehow I was able to use this last one for several trips of 3 days each. I've found that with an electric (battery) toothbrush, toothpaste lasts longer than otherwise. 0.6 (and 0.2 of course) is so small, you can easily put it in your pocket--and not deal with the 3-1-1 rule.