So last.fm have announced they will be offering a streaming service in the near future which will allow users to play any given track whenever they want.
As of today, you can play full-length tracks and entire albums for free on the Last.fm website.
I hope that this ends up being a real step forward in a music subscription service. I want something like Rhapsody but with the ability to play the music on any computer or with just a web browser. Hopefully with DRM going the way of the dodo on music it seems like that has a much larger chance of occurring.
Here is to hoping the music labels allow real innovation to occur.