Music streaming service Spotify will be available as an iPhone app later this year, and the company is working on developing the service for other portable devices too.
It's part of big expansion plans for the music site, which has more than a million users in the UK.
Speaking about the plan to go mobile, Spotify founder Daniel Ek told The Great Escape music conference in Brighton: "We want to be everywhere. We won't only do one device."
However, users who want to listen to Spotify on their mobile devices will have to pay for it.
More after the break
"Portability is an important aspect, as is interoperability with other devices," says Ek. "That's definitely something we think is a premium product that people are willing to pay for – being able to take the music with you or being able to have it working on your stereo."
The web-based service is currently free to users who accept adverts between their songs when listening on their PC or Mac. An advertising-free version is available for a monthly subscription of £9.99.
Spotify is currently available in the UK, Sweden, Norway, Finland, France and Spain. There are also plans to launch the service in the US by the end of this year, or early 2010.