Google Wallet, a new near-field communications (NFC) based payment system created by Google in partnership with MasterCard and a number of additional partners, is now available on Sprint’s Nexus S 4G. Google Nexus S users on AT&T and T-Mobile are left out in the cold for now. MasterCard confirmed that an over-the-air update is being pushed to the Nexus S 4G on Monday that will automatically install the Google Wallet app. Once it is installed, users can enter in their MasterCard information and use their Nexus S 4G to make tap-and-go payments at 300,000 PayPass locations around the world. Initial users will receive a $10 bonus on their Google Prepaid MasterCard accounts for being an early adopter, too. Google also announced on Monday that Visa, Discover and American Express have provided their NFC specifications so that those payment options can be added to Google Wallet in the future. Read on for a quick video of Google Wallet in action.