Scrobble to last.fm with iTunes home sharing
It can be done, using the following steps:


In iTunes, go to Preferences > Sharing Preferences. There is an option there called 'Home sharing computers and devices update play counts'. Turn that on.
After you've listened to some music, open the last.fm Scrobbler application on your computer, and it should prompt you to scrobble what you've just listened to.


Works for me - I'm using iTunes 11 on a Mac.