Be sure to use a stainless cup to keep liquids hot or cold for hours - and one with a snap-tight closure to prevent leaks (ala "Starbucks-style"). Fill at airport water fountains after security, transfer from airline cups to prevent spills (flight attendants may or may not fill your own cup), take out beverages from hotels and restaurants - and, for no spills and more than an 8oz cup or glass, use aboard ship at the buffet, pool or during a seminar, fill with ice and water or add Crystal Lite l