With summer days dwindling, Google (NASDAQ:GOOG) has less than two weeks to make good on its pledge to launch its Google Wallet mobile payment service.

Google Wallet is a mobile application service that will let owners of Sprint’s Samsung Nexus S 4G smartphones use their phone as a wallet at some 20 retailers and restaurants.

Bloomberg said the carrier group, which unveiled its own tap-and-pay effort in July, plans to invest $100 million to build out its mobile payment plans to challenge Wallet.

Read more, via eWeek.com.