Hailing an Uber is pretty straightforward. You launch the app, choose a pickup location and hit the "request" button. Easy. Uber's simplicity has been to the detriment of flexibility, however. For the longest time, you couldn't schedule a ride in advance -- say, if you were planning for an early flight, or an important work meeting. That's now changing, however. Following roll-outs in Seattle, London, and other parts of the UK, Uber is bringing its early booking system to New York City. Starting today, you can hail a ride anywhere between 15 minutes and 30 days in advance.