1. A method performed by a computing device, the method comprising: playing first audio information stored in a computer-readable memory at the computing device via a speaker associated with the computing device; while playing the first audio information, receiving a first set of one or more selection and playback commands selecting a first playback device and a second playback device to play the first audio information; in response to receiving the first set of one or more selection and playback commands, (i) streaming the first audio information over a local area network (LAN), wherein each of the first and second playback devices receive the streaming first audio information from either (a) the computing device or (b) the other of the first or second playback devices, and (ii) controlling, over the LAN, the first and second playback devices to play the first audio information at substantially the same time; while playing the first audio information, receiving a second set of one or more selection and playback commands selecting the first playback device and the second playback device to play second audio information from a location accessible via a wide area network (WAN); in response to receiving the second set of one or more selection and playback commands and while playing the first audio information, (i) obtaining the second audio information from the WAN location, (ii) streaming the second audio information over the LAN from the computing device, wherein each of the first and second playback devices receive the streaming second audio information from either (a) the computing device or (b) the other of the first or second playback devices and (iii) controlling, over the LAN, the first and second playback devices to play the second audio information at substantially the same time; while streaming the second audio information over the LAN from the computing device, receiving a third set of one or more selection and playback commands for the computing device to switch from playing the first audio information to playing the second audio information; and in response to receiving the third set of one or more selection and playback commands, switching from playing the first audio information to playing the second audio information.