There’s a new music subscription service on the block, and its name is Rdio. Previously in private beta, Rdio has flung open its doors and is now open to anyone in the U.S. and Canada. The Web-based service is accessible via your Mac or Windows PC thanks to a cross-platform Adobe AIR application, and there are also apps for iPhone, Android, and BlackBerry—all of which allow you to stream music from a library of seven million tracks. The Rdio Web service costs $5 a month for desktop enjoyment. The $10-a-month Radio Unlimited subscription adds smartphone streaming as well the ability to transfer songs for listening on the go.