Michael Coffey has just posted a beta of Mobbler, an S603rd Edition client that will scrobble your played music to your Last.fm account. The beta now has a very easy and simple interface where you only enter your username and password, then connect, and leave it running in the background. You can then launch your music player and let Mobbler do all the job. I have it now running on my N95-1 and it seems to function well.
Although I’m a last.fm subscriber and big fan of the concept of mobile scrobbling — and, by extension, Mobbler, I think you’d have to drag me kicking and screaming through the streets naked before I would use a Symbian Series 60 device to listen to music.