We have a ZonePlayer 80 in the study and front room, the rooms which already had a stereo; a ZonePlayer 100 in the kitchen with shiny new speakers (so my poor dirty CD walkman can get cleaned up & put away); and two controllers that are like giant iPods (one for upstairs and one for downstairs). As well as letting us having the same music playing all over the house, we can also listen to different music from the same mp3 server. And if I move rooms and want to carry on listening to the same album, I just hit the hard Zones button, and it pops up a menu, then hit Link Zones and it moves the music to the new room. It Is The Future.
 The house next door with which we share a party wall is rented out to students, so it's randomly empty depending on university holidays.