We Americans have been living with restrictions on the liquids and gels we can carry into the cabin of aircraft for years, but there are always some people who don't know what the Transportation Security Administration allows.
You can't carry half-full tubes of toothpaste or other products if they are larger than 3.4 oz (100 ml). But families can bring enough breastmilk or formula for babies or small children, and nearly blind people like myself can tote all the saline solution that's needed for their trips, too.
Ordinarily I would not recommend purchasing travel-size items, because generally speaking you pay less per ounce for larger containers. You're better off buying your own smaller reusable containers and tranferring a smaller amount into TSA-approved sizes.
But! Travel sizes offer you the opportunity to test higher-end products before you invest in a full container.
If this intrigues you, check out 3floz.com, which I found through ShopSmart magazine. The site features not only smaller packages of various beauty products but also towelettes soaked with sunscreen and other items to further assist your efforts to navigate TSA rules while still protecting yourself.