Could Amazon be planning an iPod killer? has registered the domain name, suggesting that the company may be planning to branch out into music devices. was registered yesterday by the legal department of Amazon Technologies Inc, with an contact address.

Companies often register domain names simply in order to keep them out of the hands of others, so the registration may merely be defensive. Amazon itself already owns over 7,000 domains.

But speculation into whether Amazon would launch a music player goes back over four years, when a Wall Street Journal article reported that the company was planning to rival the iPod.

The paper reported in 2006 that Amazon would launch a subscription-based music service tied into a discounted player device.

That never happened, but speculation arose again in 2007 when the company launched its downloadable music store, and last year when it released its Kindle e-book reader.

The first-generation Kindle already has MP3 playback functionality, but the feature is currently classed as “experimental”.

Amazon already has 10 million DRM-free songs available as MP3 downloads, so it has more than enough infratructure and licensing clout to step straight into iTunes territory, which could give Apple something to think about.