In the wake of exploding batteries in some laptops, airlines are taking measures to ban the use of those laptops in flight. For the year 2008 a new FAA-wide battery ban has gone into effect, and this one potentially applies to all of your gadgets -- not just your laptop.

The ban doesn't focus on a specific manufacturer or model. The new rules dictate how much lithium you are allowed to carry on a flight, and how you are permitted to do so. Lithium is of course a key component of rechargeable lithium-ion batteries, and with these new rules you are allowed to carry on and check a maximum of 25 grams of lithium.

How do you figure out just how much you have in all your gadgets? Well, there are some guidelines and examples at Safetravel.dot.gov that can help you get a good estimate, but unless you always take three or four spare batteries for your laptop along with you, chances are you have nothing to worry about.

However, it's important to note that spare batteries cannot be stored in checked baggage. So, while you can still take a second or maybe even a third laptop or cell phone battery with you, you have to keep it in your carry-on baggage, or risk it not being there when you get to your destination!