The Air has the ability to connect to devices via 3.5mm Aux or RCA connections as well as AirPlay via your WiFi network or Bluetooth.
AirPlay works with iPhone, iPod Touch and iPad devices with iOS 4.3.3 or later as well as Mac and PC with iTunes 10.2.2 or later.
Any device with Bluetooth functionality should be compatible for connecting to the Air via Bluetooth.
You can also connect any device with either a 3.5mm or RCA phono output to the analogue inputs of the Air. The analogue input is selected by pressing the X button on the top of the Air.