A new web radio service called Slacker has launched in beta today. When it unveils its associated music player later this year, it will aim to make internet radio portable and even compete with the mighty iPod.

Slacker has bagged $13.5m (£7m) in funding from Sevin Rosen, Austin Ventures and Mission Ventures, and its team includes Dennis Mudd, who was previously CEO at Musicmatch.

Like other web music services Last.fm and Pandora, Slacker allows you to tell it which tracks you like or dislike, and learns from your listening habits to play you music that matches your tastes.

You can choose from a preset list of stations chosen by genre, or listen to ‘Artist Radio’, which is a playlist based on that artist and related music.

The basic service is free to use and supported by advertising. Premium options are also available and will give you more features and flexibility.

The interesting aspect of Slacker is not the web radio service, but the planned Slacker Portable Player. The device allows you to listen to your Slacker radio on the move, and communicates with Slacker’s servers to keep your playlist up to date.

The ability to play tracks from your cache so you can listen to your web radio even when out of coverage is a selling point, though it remains to be seen whether or not people will pay $150 (£77) or more for a Slacker player instead of an iPod.