First CBS releases their iPhone Player and now another project close to my heart has been released by Last.FM — a "full blown Last.FM app on Apple’s mobile platforms that is nothing short of insanely great."
Log in or signup to Last.FM and once you start streaming something, you’ll have access to the familiar Last.FM contextual items (love, ban, skip… tagging will be in the next version). You can also check out the artist bio, similar artists and events (particularly cool). If there are current events for the now playing artists, you can specify if you’re attending or not and go to a Google map for the event location.
NOTE: There are no background applications allowed on the iPhone/Touch. There are several implications to this, but what it mostly means is any time you click a link that loads Safari, the music will stop and you’ll have to restart the app. This means event maps, and bio links. We’re looking at alternatives, but for now that’s the breaks.