Contactless payments have been something of a curiosity in the credit card industry. MasterCard's PayPass has been around for the better part of a decade, but merchants and banks alike seem hesitant to adopt the technology required to make the system work, and inconsistent implementation adds to the confusion -- particularly for customers. Google's new mobile phone-based Wallet service has the potential to transform the technology from its current status as a transaction turkey, to a future as a checkout champion. But will it work? We spent a week with a Wallet-enabled Nexus S 4G, using the device to pay whenever we encountered a MasterCard PayPass terminal.