Sonos has launched an iPhone application (pictured) allowing users to control its wireless multi-room music systems from their handset. It’s available on the App Store today, and is free to download, allowing users to navigate their digital music collection, control playback, and change the volume.Sonos is flagging the app as “the only iPhone controller app that provides multi-room music control for the entire house and direct access to an infinite world of music including Last.fm and Napster”. It’s certainly a niche, although Apple’s own Remote app is a more restricted version, allowing users to stream their iTunes library from their computer to their iPhone.Hang on a mo, Last.fm? Ah, yes, that’s today’s other announcement from Sonos. The company has just released version 2.7 of its Sonos System Software, which now includes support for Last.fm, allowing people to stream tracks from the popular music service.It also lets them scrobble the tracks they play on their Sonos system to their Last.fm profile, to improve the recommendations offered by the site. So far, companies like Sonos have been more known to audiophiles and tech-heads than mainstream music fans, but this kind of multi-room music system will become more widespread in the coming years.With that in mind, the fact that they’re signing these kinds of deals with online music services now is fascinating. We met Sonos CEO John MacFarlane in London last week, and he told us that 70% of Sonos users pay for a music subscription service, and that 60% of the firm’s customers are outside the US.