I don't like to have the thought of smartphones being the most important thing about Bitcoin Transactions because almost everyone that has an active Internet connection would have the opportunity to build a Bitcoin Wallet and do transactions in real-time. Since the whole process of building a Bitcoin Wallet only consists of about 5 minutes of the person's time, the person has the option to receive money without the need of a smartphone -he could just have a print out of the Wallet information and the money will get transferred to it by the sender.