The Atlantic explains the logic behind this strange idea…
Basically, [Tim] Geithner’s last act as Treasury Secretary is to create a platinum coin worth $1 trillion, throw it in the country’s bank account and protect us all from a prolonged headache over raising the debt ceiling. Should he do that, the President no longer has to ask Congress to raise the debt ceiling. Creating a platinum $1 trillion coin would circumvent the debt ceiling fight.
According to the article, there’s a law – the same one that allows for commemorative coins – that would let Geithner make a platinum coin of any denomination he likes. The idea sounds crazy, but it’s easy to see why people would compare it to the alternative. After all, we’ve just seen politicians waiting past their self-imposed New Year’s deadline to hash out a partial deal on everyone’s tax rates. And the last time there was a fight over the debt ceiling, the bickering cost the U.S. its perfect credit rating.