Testing a Sonos Digital Music System was like staying at a four-star hotel on somebody else's dime. The system lets you stream music around a house using Ethernet or mesh wireless as the connection medium. I had a loaner system a few months ago for a review in Personal Tech Pipeline, and have been waiting for additional Macintosh support, which Sonos just provided.
The heart of the Sonos system is the ZonePlayer, a hub that powers a set of high-wattage speakers or pumps input and output through stereo and RCA component jacks. You can have up to 32 ZonePlayers scattered throughout your house (or castle, if you own that many) linked via Ethernet or wireless networking. For example, you can bring input from one Sonos ZonePlayer - say, an iPod playing through its stereo output into a Sonos input - to that ZonePlayer or one or more others.
A handheld controller or similar desktop software lets you create ZonePlayer groups, create queues for each group, and control other settings. The software is now available for the Mac; it was Windows only when Sonos first shipped the system.
The software controller is really a critical part of the system. You can install the software on every machine on the network and use any machine to then control any ZonePlayer or set of ZonePlayers. With the software controller, you could also choose not to purchase the separately sold $400 hardware controller (which is effectively $200 when purchased as part of an introductory bundle).
Music that can be played through the Sonos system may be stored on any number of computers; collections can be broken up and still be made available across the entire system through aggregation that Sonos performs. Sonos uses Samba file sharing to gain access to stored music; using Mac OS X's Samba support worked fine in my testing.
Sonos also now supports Windows Media Audio (WMA) Internet radio stations, which is a nice addition, and lets iTunes users access their iTunes library within Sonos's system. It still can't play Apple's AAC-FairPlay digital rights managed songs from the iTunes Music Store, however, since Apple has refused to license FairPlay to anyone.
The system is pricey, but wonderful. It works precisely as advertised. ZonePlayers are $500 each; controllers cost $400 each. A bundle of two ZonePlayers and one hardware controller is $1,200, or $200 off separate purchase.