The iTunes Tagging will be a free service, available to all consumers with HD Radio receivers that feature a special Tag button. Users listen to the song on the FM, they like and mark it (“tag” it) to be purchased from iTunes.

The new service is a joint venture of Apple, iBiquity Digital, and major radio broadcasting groups, including Clear Channel.

Research consistently shows that radio is the predominant source of music discovery. Now, with iTunes Tagging, HD Radio technology provides a cool new way to capture the songs listeners discover, buy them on iTunes and then enjoy them. We are especially pleased that so many broadcasters came together so quickly for the initial launch.” (Bob Struble, CEO of iBiquity Digital, the developer of HD Radio technology)

The first HD radio devices to include the Tag button will be coming from Polk (Polk Audio I-Sonic Entertainment System 2) and JBL (JBL iHD). The new devices don’t have a price tag yet, only a vague release date: this holiday shopping season. More devices are scheduled to follow in early 2008.