Now, with iPhone 3.0, there is an application called iScrobbler that allows you to scrobble directly from your phone.  You add your music (as much or as little as you want) and listen to it from inside the app.  As long as the app is open, your played tracks will be scrobbled.  Not as elegant as a small application running in the background…but it’s a start. According to a post in the last.fm forums about the app, you can also start playing tracks on your iPod, and as long as you start the app before the first song ends, it will scrobble that track and all tracks played until the app is closed.

I have downloaded it, but not used it yet.  My biggest complaints so far are that I really hate the color scheme–it is an inelegant mix of orange and yellow that quite frankly hurts my eyes–and the track information (artist, album, title) is in a very small font.  But, like I said, it’s a start.  I look forward to seeing this app grow and possibly seeing something cooked up that will allow background scrobbling in iPhone 3.0.