As far as the Transportation Security Administration (TSA) is concerned, sharp objects are a no-go in carry-on baggage. You may include items such as knives, box cutters and meat cleavers in checked luggage. Exceptions for carry-on luggage include pointed-tip scissors with blades shorter than four inches and supplies, such as needles, that are medically necessary. Other items permitted in checked bags, but not carry-ons include most large sporting goods, firearms, self-defense and martial arts-related items and most tools greater than seven inches in length.
Based on explosives testing conducted since August, 2006, the TSA sets rigid guidelines for how you can travel with liquid items. Liquids, gels and aerosols must follow TSA's 3-1-1 rule: One clear, zip-top plastic bag for one traveller that contains containers that are no larger than 3.4 ounces. Only certain items, such as baby formula, breast milk and medications, are exempt. They must be pre-screened and carried on-board an aircraft in "reasonable quantities," notes the TSA.
Most individual U.S. airlines have implemented charges on checked baggage. Two of the United State's biggest airlines, as of March 2010, United and American, both revised their baggage rules early in 2010. Domestic tickets purchased on or after February 1, 2010 with American Airlines carry a $25 charge for the first checked bag, $35 for the second checked bag, $100 each for checked bags three through six and $200 for the sixth and each subsequent checked bag. United has similar rules. Both airlines waive these fees for First Class customers and individuals with special status in their frequent flier programs. Southwest Airlines, as of March 2010, does not charge a fee for the first two pieces of checked luggage. Bags three through nine carry a $50 fee per piece. After that, you will pay $110 per item on Southwest. Most airlines, including Southwest, United and American, allow one carry-on bag and a small personal item (e.g., a laptop) on board at no charge.
