To keep up with with the growing proliferation of car sharing services (and their own sister company Zipcar), Avis will now let you pick your ride, extend your rental or just breeze through the car pick up process right from your phone. The updates are all part of the new Avis Now features, which launched today at 50 locations across the US and will expand to select international markets in the near future. To take advantage of Avis Now, drivers have to be enrolled in the fre