RIM, the Waterloo Ontario Company, officially launched its new music subscription service today called BBM Music. It will cost $(US) 4.99 a month and give users of Blackberry devices access to stream, store and store locally up to 50 songs, at least initially. You will be able to change up to 50% of the songs on your list each month.

RIM says the new service will allow you to discover the songs your friends are listening to as well, and you will be able to combine your songs and those of your friends to build a playlist. You will also be able to send songs or playlists to friends so they can see what you are listening to, and they can choose to listen to your selections at any time.

The service is being rolled out in Canada, the USA and Great Britain today (August 25), and will be available in other countries later this year. You can sign up for the service here.