Renewing your passport soon? You may want to craft a tinfoil sleeve to store it in. That´s because the next generation of U.S. passports, set to hit travelers´ hands by September, will come with a radio transponder and a 64-kilobyte computer chip embedded in their back covers. The chip will store the same information that´s printed in your passport, and the transponder will broadcast it to a reader synced up to an inspector´s computer. IT´s part of a cover-to-cover passport overhaul to make the document harder to counterfeit.Why the tinfoil?