As with other Sonos ZonePlayer products, the only controls on the S5 itself are volume and mute buttons. The unit is designed to be controlled via the free Sonos iPhone App (running on an iPhone or iPod Touch). Alternately, it can be controlled via a Windows or Mac application, or with one of Sonos's dedicated wireless remotes.
The S5's back panel is pretty spartan. If it's the first Sonos product in your home, you'll need to plug in an Ethernet cable to one of the two network ports. (The second one can be used for another Ethernet connection, such as a PC, TiVo, or Xbox 360.) But if you've already got a Sonos component (or the $99 wireless bridge, as we did for this demo), the only cord you'll need is for AC power.
The S5 also has a headphone jack and a line-in port as well. The handle at the top makes it easy to move from room to room (or even out to the deck).