Machines communicating by voice with other machines is a science fiction staple. But it's already being used by a bus service, Shuttl, to ease passenger boarding.
Instead of scanning a device with a barcode or using Near Field Communications (NFC), a Shuttl passenger uses her smartphone to transmit an R2D2-like sound to the driver's phone. An app sends a melodic and swift sound that completes the transaction. It doesn't need wireless connectivity -- or patience.
The technology is made by a U.K.-based firm called Chirp, and is aimed at the business-to-business market. Its competition is wireless technology.