I am looking for something which will let me hear audio from backgrounded user accounts.

Before Tiger, all audio came out, regardless of which account it came from. Now it's only the frontmost user who gets access to the audio.

I realise this is a security 'fix' but here at home, where my mac is shared by me and my girlfriend, and no-one else, we'd prefer to keep all our music in one account, and not have to interrupt iTunes just because someone wants to check their mail.

Any ideas?