It's called MotoCast on the Razr and it's great. I set up my pc so that my Razr can access My Pictures, My Music and My Documents using Gallery, Music and Files. It will also sync iTunes playlists and your music folder if you like.
Agree with Sally. Admittedly not having tried ZumoCast, MotoCast is fantastic enabling me to travel light, yet having access to all my files remotely without occupying internal or SD storage. Very easy to get started and use.
My wife is thinking of getting a RZR. I have a Bionic. My question is with the Bionic you at times have to do a battery pull. How does one accomplish that with the RZR?