I agree. Simply repeal legal tender. Done.
Congress has a constitutional mandate to define weight and measure of gold and silver. Do it. Done.
Now AmEx, Visa, Mastercard, Wal Mart, Toyota, McDonnalds, BFI, and any average Joe in his garage can make money that adheres to that standard.
But NOT the government. NEVER the government. Do not trust the government with your money. Ever.