You CAN pack liquid in checed luggage, not carryon. We ALWAYS pack liquids in checked luggage as I'm too cheap to pay $2 for a bottle of water. You CAN'T pack liquids in carryons though, unless it complies with their 3-1-1 rule, which is three ounces or less of whatever, in a 1 quart ziploc bag, and 1 bag per person. So you could carryon a 2.9 ounce bottle of sunscreen, a 3 ounce bottle of shampoo, a three ounce bottle of hair gel, and 1 ounce bottle of contact lens cleaner as long as it fit in a 1 quart ziploc.