For all mobile device enthusiasts who also travel a lot, you should know some of the new rules that come into effect on January.2008 people banned from flying in the United StatesS.Carry spare lithium batteries in checked baggage.The new restrictions announced by the U. S. Department of Transport (DOT) are designed to reduce the risk of aircraft fires.Lithium batteries are considered a possible cause in several aircraft fires.If passengers are installed in devices such as laptops or digital cameras, they can still carry lithium batteries in checked baggage.But DOT says loose batteries need to be put in plastic bags to carry on the plane as hand luggage.The danger of lithium batteries is that they can provide extremely high current and can quickly drain the charge in Short Circuitcircuited.A too-The rapid discharge of lithium batteries can lead to dangerous overheating and may cause an explosion.On February 2006, a combined parcel service flight landed at Philadelphia International Airport after the crew found the goods on fire.The National Transportation Safety Board later said it found several burnt laptop batteries on the plane and could not rule out that they were the possible cause of the fire.The rules also limit each passenger to two "extensions-Life of lithium batteries.These batteries are large in size, equivalent to more than 8 grams of lithium.See safetravel for the list of restrictions.dot.gov.