An iPhone, of course, would be a more elegant solution that this Hookup lanyard contraption, but if you insist on carrying a Nano and a cell phone...

The Hookup attachment connects to your phone via Bluetooth. A call comes in, and the number is displayed on the Nano's screen. You can answer the call and chat via an inline mic on the earbud cord. It'll be available in the spring for $70. Seriously, if you require this ornate a solution, will you please just buy an iPhone?