Microsoft formally announced its highly anticipated iPod rival Zune digital media player, and the key differentiator is wireless. Zune, which will be out in time for Christmas, will include the ability to share and purchase music via WiFi as well as an unlimited subscription plan. This idea of a shared community, much like what Microsoft has done with the Xbox Live service, means users can share and receive songs from others and purchase the song or add it to the subscription plan. This sharing is exactly the notion Helio CEO Sky Dayton was talking about during yesterday's keynote at the CTIA I.T. show. He said one third of the company's game downloads have been gifted or begged.