As we all wait for the latest must-have device from Apple (NASDAQ:AAPL), the next game changer from Cupertino may be a service, not a gizmo or gadget.

With the world of mobile payments in its infancy, the true power of iTunes and its huge database of user information remains essentially untapped. With Google Wallet having yet to gain any major traction, eBay's (NASDAQ:EBAY) PayPal is battling Square for the top spot in a market that is estimated to reach $1 trillion by 2016.

In the video below, Fool.com contributor Doug Ehrman discusses how Apple may capitalize on this new area of technology and why it represents such a critical opportunity.