This isn't that new (went into effect Jan 1, 2008), but given the usage of laptops, cameras, cell-phones, and other small electronics, I thought I'd post a link to the FAA guidelines for traveling with spare lithium-ion batteries. If you carry these, you want to put them in your carry-on rather than your checked luggage, be aware of the limits in the number of spare batteries you can carry, and pack them safely.