Apple, iBiquity Digital, and radio broadcasting groups have unveiled the result of an industry-wide initiative to create a new, free service in the States called "iTunes Tagging".

iTunes Tagging enables consumers using HD radio receivers (a bit like DAB) that have been equipped with a special "Tag" button, to "tag" songs that they hear on the FM dial to buy later on iTunes.

"iTunes tagging takes music discovery on the radio to the next level", said Greg Joswiak, Apple's vice president of iPod product marketing.

"When a song plays on your HD radio that you like, a simple push of a button will tag it and later give you the chance to preview, purchase, and enjoy it with iTunes and your iPod."

Several major broadcasters will implement iTunes Tagging, initially across hundreds of stations. Additional stations and broadcast groups are expected to join soon, with a formal announcement of participating groups planned for later this year.

The new Polk i-Sonic Entertainment System 2 and the JBL iHD will both include the Tag button and will be available by Christmas in the States.

Here in the UK, Pure are currently working on a Buy-It-Now feature for DAB radio with no dates yet confirmed while's "Audioscrobbler" feature can recommend tunes that listeners might like to purchase.