Summary: <p>On today's Planet Money, more twists and turns in our story about the more than one billion dollar coins sitting unused in government vaults:<br><br>We talk to self-described 'travel hackers' who use frequent-flier mile credit cards to buy dollar coins and pile up miles.<br><br>And we learn that the U.S. Mint — just today! — said it would stop letting people use credit cards to buy the coins.<br><br>Also on the show: Why they love U.S. dollar coins in Ecuador.</p>
