Vodafone has just launched Real-Time Top 40, to answer the question, what are you listening to? The automatically updating top 40 music chart (designed for the UK) is based on your tweeting behaviors, and provides a nifty look at the most popular artists and songs being talked about. The site also provides a quick way to vote for and buy tracks, and influence music trends.
Real-Time Top 40 instantly updates based on tweet activity, which means that you can tweet with the artist and track you're listening to and directly affect the dynamically updating chart.
The Vodafone venture goes hand-in-hand with marketing the telecommunications company's cell phone service. According to the site, all the tracks in the top 40 found can also be found in their music store, with customers able to download DRM free tracks at "49p per track and £7.99 per album" to their mobile phones.