When it rains, it pours: The Associated Press is reporting that Napster Inc. said Sunday it will begin selling music downloads as unprotected MP3 files in the spring, joining other online retailers.

The file format change will apply "only to single tracks and album purchases," according to a company press release. Tracks downloaded as part of the company's music subscription service will continue to have copyright restrictions, the report said.

What's interesting about all of this is that if everyone is selling similar MP3 files, customers can buy from whatever store they want, instead of having to match up their gadgets with "approved" online stores. Previously, iPod owners would buy music mainly from the iTunes Store, while Zune fans would get them from Microsoft's Zune Marketplace and Creative or iriver MP3 player owners would choose from Napster, Yahoo or one of the other PlaysForSure services.

Napster to sell music with fewer restrictions [AP via CNNMoney.com]