PayPal imagines a future in which cash is obsolete, as are wallets. We will buy movie tickets by touching a movie poster on the street and order drinks from a touchscreen embedded in the bar. In PayPal’s futuristic world, software developers outside the company will create these alternate ways to pay using PayPal’s technology. That future could come as soon as Nov. 3, when PayPal will open its platform to developers who want to build payment applications. There has been considerably less innovat